This was part of a group of heavyweight contenders Table of Comparisons cards issued by ESCO. Here's Dempsey-Tunney:
One or the other of the vital stats is incorrect; Dempsey was born in 1895, Tunney in 1897. If I had to bet, I would guess that Tunney's age was incorrectly stated at the time the art was created; in 1925 he would have been 28 and Dempsey would have been 30. Some others:
I don't think the age given for Tunney is correct. The Sharkey-Tunney card says he is 26 but the image dates to a few years later. Also, in 1923 he was still fighting as a light-heavyweight. Jack Sharkey (born October 1902) is listed as 24, which would put the card at late 1926.