Ahhhh ... it's a tough putt to grade any coin by photos ... yet alone these classic silver commemorative where every example has it's own high points for wear and strike characteristics.
PG can apply the following observations to determine in-hand if this is an MS coin ... high point on the obverse is the right thigh of the Minuteman adjacent to where he is holding his rifle. High point on the reverse is the lower left corner of the wooden structure directly above the letter "R" of "Old Belfry"
I believe this to be an MS coin unless PG writes back and reports wear/rub in the two specific spots I suggested. Then ... all bets are off and we conclude AU58 slider.

That said ... my thoughts on this lovely coin FWIW ...
Quote:
dipped. The lexington boxes usually give a tone to the coins they hold
I'm seeing evidence of original luster throughout the coin ... suggest that perhaps the seller married an original box with another coin

... PG can advise on the quality of the luster and evidence of a prior dipping ... not that it matters to the grade, and this coin IMHO would pass any
TPG scrutiny relative to altered surfaces.
To help me give an honest opinion I pulled out my PCGS MS65 example ... note this coin was rejected by CAC ... so this should be considered the lower end of MS65 grade.
Not trying to hijack the thread ... but the comparison photo might be helpful to note differences between a PCGS certified coin and PG lovely example ..

Sooo ... PG coin has cleaner fields ... note the obverse bag hits and marks on my example.
My example has more obvious 'spark' from luster ... but luster is the toughest thing to capture in a coin photo ... and that might be the case here.
I have no issues with the surfaces of the obverse portrait of the Minuteman ... although I do wonder what is going on with the fields above the plow in his left hand?
There is a significant bag-hit on the reverse on the letter "D" of "OLD BELFRY" ...
Other than that the two coins appear to be equivalent to my eye ... and based on PG photo ... to be equivalent in grade as well.
Soooo ... assuming PG can verify no rub/wear on the high points ... and true original luster ... my vote is ..
MS65 and should be able to be certified as such by a
TPG.
Lovely coin PG .. and a true score if you actually plucked an MS65 at the price you paid.

BTW ... it would be remiss of me not to mention that Chester Beach designed this coin ... he of Hudson Half and other coin fame ... one of my favorite designers in this series ... and the final approval of Mr. Beach models was made by Commission of Fine Arts member James Earl Fraser ... whom we know for his
Buffalo nickel design and obverse of the Oregon Trail Half.
Gotta love the history, stories and connections that abound in this fascinating and under-collected series.
Cripes ... apologize if needed for the long reply

... PG is our collecting buddy and I felt that I owed him the courtesy of hearing my thoughts.
David
Take a look at my other hobby ...
http://www.jk-dk.art