Hummmmm......
I vote RIGHT. The coin is more sharply struck, has more details and the color is more even. It's just a soak in xylene away from being a nice coin. The black crud looks easily removable to me. It's just loose surface stuff. It has a much nicer deep brown patina that collectors desire.
The left coin has a molted appearence, probably from an unintentional cleaning at the bottom of a cup holder. LOL It also has a harsh scratch in the most major field on the coin. I will also tell you the black marks on the left coin are irremovable. Those are deep down into the planchet.
Shameless plug....but...if that's verdigris on the right coin, hard to tell with a scanner, that could be removed in 5-10 minutes with VERDI-GONE™ at full strength. And it wouldn't change the patina at all.

Lincoln Cent Lover!VERDI-CARE™ INVENTOR
https://verdi.care/
Edited by BadThad
09/06/2008 12:33 am