The off-color portion of the coin also goes across Lincoln's shoulder and chest. It could be an improperly mixed alloy or an imbed. Hard to tell from the photos. As far as being an RPM we would need a better, close-up photo of the MM. (Please try to take your photos straight-on rather than at an angle.)
I am pretty sure that is not a lamination. There is a significant increase in he shine in that area, My guess would be glue or tape
A lamination is bubbled at the very least and almost always cracked or peeling. Unless you took a horrible picture, yours is none of the above. My guess is a good solvent will remove it.
