FNB of Antioch, bought on Ebay for $5, Same size as a Morgan or Bullion oz rds, weighs 1 oz troy. Cant find anything on it on Google, the seller thought it was plated but it's atleast .900.
It was probably a giveaway by the bank from years ago when silver was much cheaper. (With a motto of "Honest value never fails" I would doubt that it is plated. It would just be too hypocritical. Touting honest value on a plated round.) It's probably the FNB of Antioch IL. The bank is still in operation, you might try contacting them to see if they can tell you anything about it.
I think that's the right idea conder, nothing on the rim but blue/pink toning, I too love the ship(Constitution)
