Looks like these dies were scrubbed up so I'm thinking the fat part of the top right leg of the N is just where they didn't scrub. Or maybe chipping around the edges widening that part them rounded from the scrubbing. Anyway, what do you all think?
That's a relatively common spot for a clash impact on a Lincoln die. Wonder if a strong clash caused the N to chip? It'd explain the polishing as well.
I am going to guess it was a strike-through on a previous coin. Whatever was being stuck-through damaged the die. That looks awfully smooth to be just an ordinary die chip. I am not sure how you could prove it sine the result would be in essence a die chip.
Like I said, at this stage it is going to be difficult at best to prove what the originally caused it, but that looks to be awfully smooth and uniform to be just a standard die chip.