I doubt there is anything to this. It just jumped out at me while glassing. The tops of the letters of US of A are thinner than they should be. It's not like a grease filled die. Its like the die wasn't hubbed as strongly near the top rim. Is there anything to it or not? Thanks!
Probably due to die abrasion, there was likely a clash that the mint tried to remove and they thinned the letters out doing so. Keep up the hunt!