I used the term "impaired proof" at a local coin show once. The dealer looked at me like I was nuts (he was correct on that point), but then asked "What the hell is an impaired proof? A proof is a proof." I like the way he was thinking. I mean it is a proof no matter what condition it is in. PF1 through PF70. “And so it goes...”
The damage is consistent with perhaps laying at the bottom of someone's tool box in the trunk of their vehicle for many years. Circulation like from sharp edges of metal tools, nails, screws, nuts & bolts. I've actually come across three different proof quarters that I got from the quarter change machine at the local carwash. A Bicentennial (1976), 1984, and a 2004. All still had most, if not all of the frost still present.