John, I had no Idea there were that many different backs. I have been making regular donations to St. Argostina in Lawrenceburg, IN since they opened and the only two backs I have seen are the ones I posted. According to the back of one of your cards, The Lawrenceburg boat must be the newest, So I'm guessing the other cards are from the other Argosy boats. I have also noticed different type styles used in printing peoples names and numbers on the front of the cards. I guess each machine spittin' the card can be set differently. I suppose this would not be a real card variation.
Roy