1. a 1952 S/D (Or what appears to be a faded S near the D) I have done a lot of research and know of a 1944 D/S penny but what about a 1952 NO known examples I can find. 2. A 1987 ZINC penny, the copper only is on the rim of the penny, the obverse and revers is pure exposed zinc. Makes me wonder if this is a possible lab experiment. I wish I had a camera, any ideas?
As for #2, that's probably exactly what it is. #1 - you say "near" the D. If the coin is an over mint mark it will not be near, it will be under the mint mark. So you are probably just seeing a mark that looks like an S.
