zadok

...dont get locked in on comparing SP to Proof, the subject is much broader than just that simple definition which only encompasses a narrow slice of coin production processes n intent...its not like a one size fits all definition....

is it bigger than a breadbox?....

"Enhanced" business strikes?  I don't know which sounds worse, qualifying a term whose etymology I challenge anyone to trace, or characterizing, of all things, one of the first coins minted of the first year of its series as a "Presentation Piece," despite exhibiting severe PMD on its obverse.
Is the above coin, whether SP or not, something you would feel comfortable presenting to someone, whether a close colleague or official dignitary?  No, never!  However the coin was iredeemably damaged, it no longer is what it once was. It is now a common, circulation strike coin. It is not enhanced.  If anything, it is grossly degraded and certification would be appropriate if it were intended as a gift to the submitter's worst enemy.

Toning that is considered "enhancing" or "attractive" is part of this nebulous factor as considered by the grading services, as I understand it.  

Nyet! Nyet! Learned colleague!  Toning, per se, is not one of the five (5) variables which may lawfully be considered by any TPGS in assigning a grade.  1. STRIKE, 2. PRESERVATION, 3. LUSTER, 4. COLOR, and 5. ATTRACTIVENESS (Eye Appeal).  Full stop!   🐓 

A coin with a reeded edge that was struck with a partial collar would have a portion of its edge without reeding, in this case the portion of the edge nearest the reverse.  See https://www.error-ref.com/?s=partial+collar. This coin appears to have the entire edge reeded. It would be helpful to have a photo of the entire edge adjacent to the "finned" area.  I still think that the anomaly is most likely the result of a misaligned (angled) obverse die.

...same reason diamond graders have real diamonds in their master sets...u dont have to have every date n mint to have a grading set....

Beats me if it is an AI error or just the person cataloging it. Pretty weird listing in any event.

...u will note in his design submissions he produced two separate designs for the 1/2 pence n the committee chose the pig design, n yes the committee did request that he alter his designs slightly...it was interesting that the committee evaluated the designs for each denomination individually in a blind test n that metcalf's designs were chosen in all 8 cases, the overall series designs were not chosen as a set but it ironically it turned out that way...i have copies of all of the designs from all 7 artists n its interesting to compare them the same way that the committee evaluated them....

...no one ever insinuated  those pcs were commissioned or produced by anyone other than the originator, there r just some persons who feel they must have the last say on everything even if they know nothing of what they r speaking of, but guess it goes with the forum territory...one just has to consider the source n dismiss it for what it is...in this case ur point is well taken, patterns could n r produced by many different sources n do not need be from any gov't agency...european auctions r replete with many such items, i personally would not refer to them as medals or tokens for several different reasons...models n patterns could be used interchangeably but i think they r usually associated as being made of different materials but that too is subjective...ur suggestion of design pattern fits accurately...many of the worlds n quasi-official expositions n fairs have non-gov't authorized numismatic items n many of those have known patterns that were struck....

...duh...no one said it was, the discussion already established that...but it is not a token, all patterns r not issued by gov'ts or did u decide to just make that up...u should stick with US dumpster documents n not try speaking for the Ireland mint, im pretty sure u have not been anointed spokesperson for them...

...the ones i purchased were thru a third party from his widow, i did know a couple of dealers who had a few patterns that they had purchased...as to whether he personally distributed any i can not say...i do have the names of the dealers that had the patterns for sale but am not certain who was the source for those pcs....

...morbiducci patterns do show up from time to time n the prices have escalated 10 fold over the past 50+ years since i purchased my own...i do believe u r correct in that morbiducci had a few patterns struck privately, the original model submissions were not presented as actual coins but as designs...interestingly, there were a total of 66 models submitted by 7 different artists, other than the designs the only patterns i have seen were those created by morbiducci....

...so sad....

...diminishing returns, from both ends of the stick...the cost to implement n program will far outweigh the return, the people that it replaces wont be there to oversee the net results n then the lower end collector or speculator that looks for these minor varieties to generate marginal returns will quit looking because its already been done...cherry picking will be over, theres no picking if there r no cherries...i can see the return of the local un-cataloged estate sale being the high point for the collector, un-certified coins will be the looked-for items...profits/sales may be the driving force but just mite drive the numismatic vehicle off the cliff...this approach is very similar to the big chain stores implementing the self-checkout lanes, results...loss of margins, loss of customers, loss of service, loss of employees n now major backtracking....

...i guess what comes to mind is...do we even need or want that degree of differentiation for coins?...variety collectors r a miniscule segment of the collector base, i am one n i dont feel that i need it nor want it...after all AI is only operational as long as there is a grid for it to exist on...

...i can appreciate ur interest in the research of these coins n desire to document the same but dubious bout collectors being enthused to ship their coins thru the maze of usps, ups, fedex n placing their coins unnecessairly at risk, plus at their expense n there is the privacy concerns bout ownership, some collectors prefer to keep their private collections just that, private...i for one will pass...u mite have better luck if u attempted to have the owners bring their coins to a central location e.g. world fair of money n u obtain ur desired photographs n annotations there? just a thought....

...fedex insurance does not cover rare coins regardless of declared value....

...dont forget to breathe thru that straw u r clutching....

You're trying to compare two coins that appeal to two largely different groups of collectors, those who try to obtain coins with the highest awarded numerical grades for their registry sets and those who collect mint errors. (The NGC Registry doesn't even allow coins attributed as mint errors.)  The NGC Price Guide has no price for a MS 68 graded 1976 clad Bicentennial quarter, while the PCGS Price Guide lists it at $4,500. Each error coin is essentially unique and commands its own price, so you can't compare this particular coin with the certified populations of pieces graded "MS 68."
   You could check auction records for each of these coins and determine what each has actually realized at any public sale.  Which one is "more rare and valuable" is inherently a matter for conjecture.

...hoards n accumulations a collection they do not make....

...true plus a few others that were privately distributed, contrary to what one so-called "expert" espouses here n elsewhere....

...could u differentiate tween ape-poopy n monkey-s..t?....

He was not real. It happens on the forum all the time.  AI has the capability to do all sorts of stuff HC and why bring this up again. It just takes up Time + Space.

But ya gotta be careful and check the plumbing.