Here is a link to a 10 card strip with Gehrig...
https://huntauctions.com/phone/image...140&lot_num=18
My edit is to add that I am not sure what, if anything, can be inferred from the boxers on that strip but with the inclusion of Hank Gowdy as a NY Giant, it closely supports Phil's theory. Gowdy was on the Giants for a minute in 1911 but would return as a back up catcher in the 1923-25 seasons.