No, they most certainly don't, at least not in the context of his question. OP, If possible, please remove the coin from the flip and re-photograph. If not possible (which I assume to be the case), I'm not comfortable voicing an opinion other than worst case, but probably isn't much help to you.
I believe it's possibly been in jewelry, in a 3-prong holder whose remnants are visible below the date and at the two U's in PLURIBUS. The surfaces are also quite suspect. No, I don't think it straight-grades.
Agreed, and what I usually say. If the OP is asking if it would clean slab, that is a very different question