There is no telling what may have caused the discoloration while it was in circulation. The lines look they may be part of a fingerprint. Chris
What about the P on his head. If you look closely there are faintly seen numbers right before the P. Don’t think the lines are finger prints. Will not wipe off.
It's amazing what things the mind can come up with when you are intent on finding something, anything, wrong on a coin. As for the fingerprint, the oils of the skin will actually etch into the coin metal which makes it impossible to remove it. Chris