There is 23 Topps Gallery of Champions sets. Dan has fixed a few of the numbering issues. I did IRs for the rest except the 1991 3 sets. As there are no images of the backs to get the numbers so these will have to be looked into a lot better than what I see at this point.
Basely there are 3 sets each year. Aluminum, Bronze and Silver. Not being into baseball I'm not sure that the 3 sets have the same card/number but made from different material. As some cards do not have an image of the back I'm not sure if we want to use the number from one of the other sets (same year)