While not common, I have seen the back of 19th century cabinet mounts contain print specific to the photo on front. I have an 1886 cabinet of a baseball game in progress with printed information about the game on back.

I believe that you will find there is a big difference in back printing on "trade cards" and CDV's. CDV's generally have little info other a photographers info as he wanted to sell more of them. Trade cards were for the merchants benefit to advertise and generally have a lot more information.

I think this card if in fact is 1 piece and not glued together has been severely cut down and could in fact be from a larger size trade card from 10-20 years after the death of Creighton. It has no resemblance of a CDV circa 1860-1870's.

Scott

Another Creighton surfaces in NY Library:

Hidden Treasure Discovered in NYPL’s Spalding Collection