I was just getting ready to 2x2 this one as RPM-004 when I decided to take one more look.
I noticed an anomaly on the obverse behind Lincoln's ear about where he took one from J.W. Booth.
From the knowledge I have attained, these are my observations;
It appears to be a chunk of the die busted off (hammer die) and got shoved around a little bit right there, until it flipped over and ended up struck in the coin.
There appears to be to me, an almost reverse inclusion to the right of the retained chip.
If you want, I could try to pop it out!
Looks like around the top of the ear is showing some delamination as well.
Considering the overall condition of this example, is it not odd that it looks like Abe's got a slug in there?





Could be the assaination cent! Just kidding about popping it out.