I know this coin is in bad shape. I see the letter U on his head just behind the ear. The U actually appears to be stamped over the ear. There also appears to be a sliver missing between the date and the bust. On the reverse side there is a long impression cutting across the monument. And yes the coin is slightly bent and the bend aligns with the impression. Any thoughts on this would be appreciated?
Grease and debris can built up within a device and become quite hard...resulting in missing features on some strikes. Occasionally, the rock-hard gunk in these "filled dies" breaks free and is pressed into a coin at some random position. Your coin looks like the "U" in UNITED on the reverse had a filled die that broke away and was pressed into the Obverse profile, just behind Lincoln's ear. That's my guess.
That is exactly what I am going to do from now on. I do have some coins that I believe are good quality.
See: "Struck through dropped filling" https://conecaonline.org/glossary-of-error-variety-terms/ I suspect these are rare, but don't know if they sell for a premium. I would hang onto it, if I were you.
