PMD - post mint damage .. meaning a company out there plated it after it was minted. worth 10 cents unless you sell it as a Novelty on ebay for slightly more to someone that doesn't know. examples on ebay https://www.ebay.com/b/Gold-Roosevelt-Dimes-1946-Now/39458/bn_26632277 some companies gold plate everything https://www.merrickmint.com/24k-gold-plated-coins.html?limit=64
no clue, the pics are not clear nor close enough. edit: actually I zoomed in another way. i assume that is damage across the head. Anyways, it was damaged by the plating process (plating is another layer of metal on it, thus making the original surface covered) and it was circulated too as it has hit and wear marks.