Jeff: Best I can do is make an educated guess about McGraw. My Matty cabinet is definitely from the Falk studio. The McGraw roto has an index number in the bottom right corner which I can't correlate with anything. This link gives the best write-up about Falk that I could find:
http://tinyurl.com/y5nze5t Seems he was primarily a photographer of theatrical subjects although there were obviously some ballplayers such as Matty and Joe's Astoria Giants and maybe McGinnity. It is reasonable but speculative to say that it is more likely that Horner's studio would get things right than Harry M. Stevens. The Sporting Life composites are generally understood, at least as far as I know, to be Horner photos yet in the 1903 example the Matty depicted is Falk's image. So the logic could work the other way, too; maybe the scorecard is correct and the McGraw might have been acquired by Horner from Falk for your 1904 team composite. Short answer: I don't know. Bitchen' postcard anyway.
(Labeled "Photos by Falk" beneath McGraw)
McGinnity cabinet image e-mailed to me by secret N54er, file name was "McGinnity-Falk", no verification proferred.
