JKK

This is the point I am always trying to make. No coin has a single value. All coins have a dealer wholesale, private collector retail, and dealer retail value; they all also have some sort of metal value (even if that's "worthless unless you had a truckload") and most retain a face value, the exceptions being those demonetized.
When people ask "what's it worth" we can do them a great service by asking "to whom?" and explaining exactly what Bob just did. We can then go back and forth over how those numbers can be estimated, and most of us have methodologies, but at least we will be offering them real economic understanding.

100% no.

That really depends on who is buying. Could you get ten dollars for it if you offered for sale to the public at a coin show, gun show, flea market, antique store, etc ? Probably. Could you get ten dollars for it if you offered it to a knowledgeable coin collector? Maybe, depending on their long-term outlook for silver prices, and the coin market in general. Could you get ten dollars if you offered it to a dealer? No, not likely. You would probably get current melt value or a bit less.

Nope.

If authentic, it might be AU-50 to 55. I'm not convinced it's authentic.

I took it to mean whatever thoughts came to mind.

I took it to mean whatever thoughts came to mind.

Common. Worn. No special value.

Neither. What you have is hot garbage. It is a badly damaged coin, probably messed up in a parking lot. Any experimentation in play would have been some kid saying: "Just how badly could I screw this coin up if I really put my mind to it and got into my dad's tools" It barely holds a value of one cent. The odds of this being a mint error are roughly equal to my odds of being named the next Dalai Lama. My best guidance to you is to spend it so that you no longer have to see such carnage.

Neither. What you have is hot garbage. It is a badly damaged coin, probably messed up in a parking lot. Any experimentation in play would have been some kid saying: "Just how badly could I screw this coin up if I really put my mind to it and got into my dad's tools" It barely holds a value of one cent. The odds of this being a mint error are roughly equal to my odds of being named the next Dalai Lama. My best guidance to you is to spend it so that you no longer have to see such carnage.

This is misleading information, Edwardram. This person has a bad habit of that, shows no signs of regret for misleading new collectors, doesn't seem to want to learn, and thus I wouldn't place any credibility in what he says.
The red toning of an uncirculated, untarnished copper or bronze coin is not the same red that you are seeing on your cent. Those are added designators to uncirculated Lincoln cents. That red color looks like freshly stripped copper wire, kind of a salmon pink, and the coin is graded something like "MS-65RD". Then it tones to part red and part brown (for example, MS-62RB), where you can still see some of the pink or at least it still looks half fresh. When that's all gone, the designator of brown shows up as "MS-64B" or whatever the main grade might be. That brown is a rich attractive chocolate brown, generally about the color of a Hershey bar. None of that is at all germane to your coin and it was imbecilic to introduce it to this conversation, which is why I expended time to demolish its relevance.
Your coin is in a different situation. It might be thought of as a variation of the "brown" designation except that the designations typically refer to uncirculated coins, which yours isn't. Yours is a normal 1969 cent with light wear and significant environmental toning which leads to a variety of shades from black to terra-cotta (yours leans that direction). Some will develop verdigris or in some cases, bronze disease. Verdigris is the bluish-green mess often seen on bronze or copper-nickel coins; yours has what might be spots of it on the obverse, 1200 (highly likely) and 400 (not as likely; could be something else). Bronze disease looks like a smurf sneezed on it, and is nasty to remove. I've done it, but the process is something most people would not care to undertake. So. While your penny would look nicer in a pleasant chocolate brown, and the reddish toning is indicative of something other than simple air exposure (not sure about sulfates or other forms from air pollution; not an actual chemist), it has zero relation to these discussions of red, red-brown, and brown. That dumpster is burning out of control.

If authentic, it might be AU-50 to 55. I'm not convinced it's authentic.

It depends what the motive is for grading. The most common grading motive is financial, sometimes accompanied by a motive to authenticate. If it's purely financial, the question is whether the best foreseeable outcome might add $50-60 to the coin's value. New collectors rarely have those sorts of coins.
Authentication is another story, but that's a lot of money to be told that one's modern worn coin is only a modern worn coin worth face value. It starts to make more sense with heavily counterfeited issues and rarities.
For some, it's sentimental: this was part of Bampaw's collection and while it turns out Bampaw wasn't the numismatist everyone assumed he was (in the land of the blind, the one-eyed person is king), he was a pretty good guy who left them a nice stash of junk silver plus a couple of LHNs he overpaid for, and they want to honor Bampaw. Fair enough. He was probably a real good guy and honoring him is easily worth the money.
The most misguided reason, though, is the assumption that this is the "right" way to collect. A part of me greatly admires that outlook because one of my pet loathings is people who cut corners, do things wrong, just don't care. Pretty much includes 90% of contractors, about that percentage of people at four-way stops, and shippers who cannot be bothered to pack correctly--everywhere that it either matters now or will matter later. It doesn't apply to coins unless you're planning on limiting your collection to just a handful. If each slabbing costs $50, by the time you reach twenty coins, you have wasted the amount that could have purchased a 1909-S VDB penny. I personally would rather have the coin than all that plastic. At our coin show, less money than that bought me a beautiful Athenian tetradrachm in great condition. So imagine I'd forgone the tet in order to get eighteen common modern coins graded, all in the belief that I was "doing it right." Yeah. There's such thing as taking "doing it right" to insane extremes, such as if one mowed one's yard with a ruler and a nail clipper.
One thing that really impresses me about NGC is that they stand aside and permit us to spend all day and well into the night telling people not to send their coins to NGC--not because NGC isn't a good place to send them (consensus is that they are at least one of the two top grading services), but because NGC evidently understands the economics well enough to realize that collectors who waste money on stupid grading decisions are likely to drift away from collecting. There are businesses that would ban anyone who even suggested not buying from the business. In fact, the main reason NGC would be my grading choice (if I ever sent a coin in, which I never have and probably never will) is because of that permissive outlook. While some of it might just be there aren't enough hours in the day (if they were, some chronic trolls and misinformers would be banned a lot sooner), I have to think part of it is policy. Enormous respect for that policy.

The MaTé (Maria Theresia thaler) is worth about an ounce of silver. Odds are it was minted in the 20th century and those are a common medium of exchange in the Yemen and Horn of Africa. Dealer probably gives you melt -5%, something like that. The Peace dollar, maybe dealer gives you $18-20--they typically give a little premium because they can always charge one. You probably get $36-38 for the two put together.

I don't think that's glue. Glue would stick up. The side photo shows indentation.
The shape looks enough like a reverse Lincoln that it's tempting to think it was a pitifully aligned vise job, but when one looks at it, the outline is incorrect.
Occam's explanation would be that it just took some real hard impacts from whatever.

There aren't separate layers. I believe you are thinking of original surfaces and mint luster.
What you originally asked about was how to detect cleaning. We don't grade (for the most part) with magnification, but we do use it to attribute it and inspect for signs of cleaning and counterfeiting, and sometimes to identify varieties. For abrasive cleaning, high magnification will reveal lateral or circular scratches. They look very different from normal wear. For chemical cleaning, it's harder. Often the cleaners do a poor job and leave some crud on the coin. Sometimes the chemical cleaning takes off the mint luster. Under normal wear situations, the protected areas (shadows of the devices) will keep mint luster longer than the raised parts; if the luster is no longer there in the shadows, but it's all bright and shiny, pretty likely it was chemically cleaned.
Be very clear on this: dull-looking is not bad. It's not bad. It might mean tarnished/toned, it might mean worn, but it is not bad. If it were in my power to mentally assault every new collector with indoctrination they could not refuse, I would force into their brains that "shiny = great" is wrong, misleading. Circulated coins are supposed to look dull, and they get spotted when cleaned because they look wrong. There is a way coins are supposed to look based on how they have been used and handled. Mint state coins can be flat dull, provided they show no trace of wear. A worn-flat Merc that shows a blast white color is much worse than the same Merc if it were dull grey, because dull grey is how worn silver looks. If it were up to me, every time someone picked up a worn coin and said to herself, "You know what? I can make this 'shinny' [that type of person usually can't spell, either] and no one will know," a coin deity would touch their privates with a cattle prod and leave it there until they recited a formula: "Shiny is not fundamentally better!"
Look for the scratches. A microscope can be helpful. Look for the crud, or for aspects of the coin that are not natural for its level of wear; a microscope can also be helpful there. Most of all, look at a lot of coins. The biggest tell is the coin doesn't look right for its age and wear. Only by looking at a lot of coins can you determine what is a normal look.
Also, remember strike weakness vs. wear. Some coin issues had a tendency not to strike up fully. Not sure which are our worst examples, but my guess would be everything silver from the 1920s--Peace dollars, SLQs, some Walkers, and such. What might look like wear might simply be the planchet's surface metal that was not forced all the way up into the high points.

What on earth is "heavy silver layer"?

There aren't separate layers. I believe you are thinking of original surfaces and mint luster.
What you originally asked about was how to detect cleaning. We don't grade (for the most part) with magnification, but we do use it to attribute it and inspect for signs of cleaning and counterfeiting, and sometimes to identify varieties. For abrasive cleaning, high magnification will reveal lateral or circular scratches. They look very different from normal wear. For chemical cleaning, it's harder. Often the cleaners do a poor job and leave some crud on the coin. Sometimes the chemical cleaning takes off the mint luster. Under normal wear situations, the protected areas (shadows of the devices) will keep mint luster longer than the raised parts; if the luster is no longer there in the shadows, but it's all bright and shiny, pretty likely it was chemically cleaned.
Be very clear on this: dull-looking is not bad. It's not bad. It might mean tarnished/toned, it might mean worn, but it is not bad. If it were in my power to mentally assault every new collector with indoctrination they could not refuse, I would force into their brains that "shiny = great" is wrong, misleading. Circulated coins are supposed to look dull, and they get spotted when cleaned because they look wrong. There is a way coins are supposed to look based on how they have been used and handled. Mint state coins can be flat dull, provided they show no trace of wear. A worn-flat Merc that shows a blast white color is much worse than the same Merc if it were dull grey, because dull grey is how worn silver looks. If it were up to me, every time someone picked up a worn coin and said to herself, "You know what? I can make this 'shinny' [that type of person usually can't spell, either] and no one will know," a coin deity would touch their privates with a cattle prod and leave it there until they recited a formula: "Shiny is not fundamentally better!"
Look for the scratches. A microscope can be helpful. Look for the crud, or for aspects of the coin that are not natural for its level of wear; a microscope can also be helpful there. Most of all, look at a lot of coins. The biggest tell is the coin doesn't look right for its age and wear. Only by looking at a lot of coins can you determine what is a normal look.
Also, remember strike weakness vs. wear. Some coin issues had a tendency not to strike up fully. Not sure which are our worst examples, but my guess would be everything silver from the 1920s--Peace dollars, SLQs, some Walkers, and such. What might look like wear might simply be the planchet's surface metal that was not forced all the way up into the high points.

What on earth is "heavy silver layer"?

Those arclike marks are damage, if that's what you are referring to. The coin, which is very common, is worth its bullion value.

No. It is worth $0.05. Nearly none of these coins from the last sixty years are going to be worth anything and you are throwing a lot of time down a rathole taking time to photograph and post them. You can keep doing it, but the conclusion will be that you aren't really paying attention to the answers.

That's very heavy wear, in which the rims are worn away (condemning it to the lower grades even if it weren't damaged). Dryer coins have a different and less natural-looking form of damage.

I think the logic is that since the coin lacks a prominent feature of the real McCoy, it would be considered an art creation. However, I'm pretty sure someone passing it off as legal tender could not fall back on that. In other words, it's illegal to possess or pass counterfeit money. If the modified reverse means it's not a US coin, just having it's no big deal. If however someone tries to pay with it, that could possibly be construed as fraud.

I think the logic is that since the coin lacks a prominent feature of the real McCoy, it would be considered an art creation. However, I'm pretty sure someone passing it off as legal tender could not fall back on that. In other words, it's illegal to possess or pass counterfeit money. If the modified reverse means it's not a US coin, just having it's no big deal. If however someone tries to pay with it, that could possibly be construed as fraud.

I think the logic is that since the coin lacks a prominent feature of the real McCoy, it would be considered an art creation. However, I'm pretty sure someone passing it off as legal tender could not fall back on that. In other words, it's illegal to possess or pass counterfeit money. If the modified reverse means it's not a US coin, just having it's no big deal. If however someone tries to pay with it, that could possibly be construed as fraud.