Sorry doesn't look like a proof to me.....and IDK if there's any 76 proofs with MPD's Nope only ms had the variety and only 1100 mintage...rims arent squared.
No pawn shop would pay up for a damaged coin , [that's a huge chuckel ]..pawn shop pays the lowest rock bottom price possible....and if they actually believe that it was indeed a proof...no way would they tell the seller.