The dark spot on the right looks like Lincoln standing and looking at his own statue. As far as Lincoln'r head..double die maybe?
Overall I think he looks pretty beefy... but I'm the king of seeing phantom "errors". On a quick search, I didn't see a listing mentioning doubling in the head. I dunno, I'm a newb and I'm figuring this out as I go.
Hot diggity! Aren't you the observant one. The coin itself look like doo... but there was enough here looking at 10X to catch my attention.
If it's a D mint, it might be this one.http://www.coppercoins.com/lincoln/diestate.php?date=1998&die_id=1998d1dr002&die_state=eds