It may just be the light or toning, but I see what
could be E-W scratches (or more likely just surface crud) above the "Y" in "TWENTY." Is it possible to get a clearer photo of this area? Here's the best enhancement of that area that I could do with the reverse photo:

The 1875 Philadelphia coins always make me pause just a bit because there are some remarkably skillful older removals of mint marks from 1875-S
Twenty Cent Pieces, and these appear from time to time, even in slabbed coins. I don't think yours is one of them, but the possible scratches make me overly cautious.
Thanks!