That's funny I was just sorting thru my "possible errors" pile today and put a blackened half with a raised bubble into acetone trying to clean it off. Now that I know it's just fire damage I can throw it back into the wild for someone else to find and wonder how it got that way. Glad I found this old thread!
I also have a dime that is not black from fire and only has the bump on the tails side and is in great condition
