I just received these in the mail from Rhys. (Thanks, Rhys.) There was a thread about the Jimmy Foxx quite awhile ago, and the group was stumped. If anyone has any more educated guesses, they would be appreciated. There's obviously a bit of additional information in the scans. First -- great players. Second, they were clearly issued in strips. Third, the uncut strip has just a touch of green along one edge. Some of the others have a touch of red along the edge. The backs are white, but underneath the white layer is a standard cardboard color layer. They are fairly thick and stiff. They measure about 1 1/2" x 1 7/8".