Mohawk

They would certainly look much nicer in a scratch free case. 

I had the exact same idea recently. Bought the compound, rubbed a little on, and took my dremel with a polishing wheel to the slab. I don’t suggest doing that. NGC will be re-slabbing that one for me on my dime. That plastic is thinner than it seems. The dremel wore a notches quickly. I tried to smooth it and I was through the slab pretty easily. If you do this do it by hand. 
 
On a related not don’t let acetone splatter on a slab either. It eats through rather quickly 😂

Dremel??   NO no no no no!! 

Definitely.  West German proof coins (and East German ones for that matter of fact) are absolutely gorgeous coins.  But as sleek and amazing as the 1974 and later West German packages are (before 1974, the packaging was basically mylar wrapping. Think 1955-1964 U.S. Proof Sets, but with stiffer plastic), they tend to get scratched up over the years.  The East German proof set packages are hardier, so they tend to hold up better.  

Очень красивая монета!

Thank you so much,
I have uploaded some better photos to show the lustre.

I am not familiar with Russian coinage or the value, but I do agree this is one very attractive coin. Others will be more help on if it makes sense to slab or not, but however you want to do it this is a keeper to be preserved. 

Very nice EF. The pleasant (JKK says "beautiful") coloring is common on these and others from the period. Many remained in bags and the sulfur from coal burning in St. Petersburg and Moscow created a gentle toning. This makes the intricate obverse designs (or reverse on the ruble) extra attractive. When poured out of a bag, these things glitter like fireflies. Gold from the same period also can have attractive toning, but not as nice as the silver. These run from $40 to $55.

I wonder if that would work for proof set cases from different countries.  I love West German proof sets....they have nice coins and very sharp packaging starting in 1974, but that packaging often looks like this:

Could be worth an experiment.

Yes Chris, I think @Mohawk has a great suggestion here.  I would personally love to see your Kennedy and what it looks like.  As opposed to posting it here on this member's thread, simply out of respect for the original poster, why not make a new thread for your coin.  I'm sure Mohawk and others would like to see it as well.  I'm sure there are other members who have not read down this far on this particular thread to see what we are talking about now.  It sounds pretty interesting and who knows, if you have a 40/60% Kennedy half, and it does in fact have rust, you may have something of value. I have never heard of a silver proof rusting.  I could only assume from what you described that you may have an off metal planchet error of sorts. If you do decide to make a thread for it, make sure you add the weight of it in 100th's of grams if you are able. Just MHO here and ya never know......   

Greg's absolutely correct.....silver and copper cannot rust.  It's metallurgically impossible.  They can develop corrosion of other kinds, especially copper, but they can't rust.  My guess is that your coin has some kind of corrosion related to the copper content.  I've seen that on 40% Kennedys before, typically along the edge of the coin.  If you post photos, we could likely tell you more about what's going on.

I'm with the others.....I'd try an acetone bath, see what kind of results you get, and go from there.

I'm with the others.....I'd try an acetone bath, see what kind of results you get, and go from there.

Ok. Now for my favorite wedding joke 😉 
What are the 3 official marriage rings?
1. The engagement ring
2.  The wedding ring
3.  The suffer ring 😂 
Congratulations buddy 👍🏼

Okay, here's one that fits my personality well:

Oh you know it!! It'll just be me, my sister, my dad, her two cousins and maybe her dad and grandmother.....it's tough with her family, though, because her mother is a malignant narcissist and a religious whack-a-doodle.  My fiancée has a very bad relationship with her mother, so that whole part of the wedding is very.......complicated.  We'll just have a few people and a pizza banquet (we're big pizza folks).  It's about as cheap of a wedding as you could imagine and the wedding gifts to each other will be......you guessed it....COINS!!! So coins will be part of the wedding as well!  I think the biggest cost will be getting her cousin in Texas up here, but that's totally worth it and vitally important.

Oh believe me, I'm marrying her.  We're officially engaged and we've been together since 2008.  Basically, we're waiting for a time where her cousin can perform the wedding for us.  He can legally officiate weddings in more....how do I say this.....custom ways, which is important to us.  We want more of a ceremony than a courthouse wedding, but we're not Christians, so we don't want that kind of wedding, either.  And she wants her cousin who lives in Texas to be her best person, so we have to wait until we can get him up here to the Finger Lakes so he can be there as well.  We'll get it all together one of these days.  In my case, the family thing is super easy.  My family is my dad and my sister, and they live about 30 minutes away, so that's not tough.  

Okay, here's one that fits my personality well:

Now that, tj, is great!!!! It's completely different in my house though.....my fiancée and I both have the bug.  We'd buy the generic food item so we could put that money into our collections! I'll have to see what I can come up with.

Oh believe me, I'm marrying her.  We're officially engaged and we've been together since 2008.  Basically, we're waiting for a time where her cousin can perform the wedding for us.  He can legally officiate weddings in more....how do I say this.....custom ways, which is important to us.  We want more of a ceremony than a courthouse wedding, but we're not Christians, so we don't want that kind of wedding, either.  And she wants her cousin who lives in Texas to be her best person, so we have to wait until we can get him up here to the Finger Lakes so he can be there as well.  We'll get it all together one of these days.  In my case, the family thing is super easy.  My family is my dad and my sister, and they live about 30 minutes away, so that's not tough.  

I actually don't have to worry about that.  Her mom has legit, diagnosable Narcissistic Personality Disorder.  It's not just an attitude with her mom, it's a real disorder.  My fiancée does not have the disorder, so I should be okay.  She's 33, so if she had NPD, it would have shown up by now.

Oh you know it!! It'll just be me, my sister, my dad, her two cousins and maybe her dad and grandmother.....it's tough with her family, though, because her mother is a malignant narcissist and a religious whack-a-doodle.  My fiancée has a very bad relationship with her mother, so that whole part of the wedding is very.......complicated.  We'll just have a few people and a pizza banquet (we're big pizza folks).  It's about as cheap of a wedding as you could imagine and the wedding gifts to each other will be......you guessed it....COINS!!! So coins will be part of the wedding as well!  I think the biggest cost will be getting her cousin in Texas up here, but that's totally worth it and vitally important.

Oh believe me, I'm marrying her.  We're officially engaged and we've been together since 2008.  Basically, we're waiting for a time where her cousin can perform the wedding for us.  He can legally officiate weddings in more....how do I say this.....custom ways, which is important to us.  We want more of a ceremony than a courthouse wedding, but we're not Christians, so we don't want that kind of wedding, either.  And she wants her cousin who lives in Texas to be her best person, so we have to wait until we can get him up here to the Finger Lakes so he can be there as well.  We'll get it all together one of these days.  In my case, the family thing is super easy.  My family is my dad and my sister, and they live about 30 minutes away, so that's not tough.  

Okay, here's one that fits my personality well:

Okay, here's one that fits my personality well: