1941 Cent

Although I'm not sure what happened to your particular coin, I can say that from my personal experience in buying old Whitman albums namely Wheat cents, it seems to me that when these folders are exposed to any amount of moisture for an extended period, the coins get irreparably tarnished, and not in a good way. I bought one incomplete set a couple years ago, and the coins were just destroyed, verdigris, etc. The other day I had the chance to buy another folder at my LCS, and declined as they were also in terrible condition, my offer would have been very low. I no longer do Whitman albums and if I do happen to come across one, I hate to say this but the coins come out and the folder goes directly into the trash. I just don't trust them.