N310 Mayo Boxers Help Needed

[monty]

I recently picked up 2 N310 Mayo Boxing cards of Sullivan & Corbett. After doing research on these cards I do not believe they are authentic. Since Boxing is not my specialty I would appreciate the opinions of some of you Boxing collectors. In the guide of American Tobacco cards the size of these cards list as 1 5/8 by 2 7/8. The cards I have measure 1 7/8 by 2 1/2. Also, on the back the boxers name is printed small red print with a card # above it. The originals do not have this on the back. In all of my research on these I could not find anything regarding reprints or fakes from this issue. The cards I have are both aged with corner wear and soiled backs. The Corbett has a minor stain on left edge. They sure appear to be old. I only saw one other with a back like this (Sullivan) and the card apparently was found in an old cigar box passed down from the family. Were there ever 'Salesman Samples" of these cards? I still have time to get a refund if they are fakes. Unfortunately, I was not able to download pictures but I feel the info I gave should be enough. Any help will be greatly appreciated!!!!!

Thanks, Monty