Found this on Beckett.com, I kind of think these are real. I can't find any evidence they were ever reprinted.
1910 Anonymous E78
The E78 set of Prize Fighters looks very much like the sets issued by the American Caramel Company but there is no sponsor information on the backs. The cards measure approximately 1 1/2" by 2 3/4" and have a color artist's rendering on the front. The card backs were printed in black and feature a roster of boxers who are included in the set. The cards are arranged below in alphabetical order.