And, here is the gold. From the "
Biographical Directory of the State of New York", published in 1900, we have the attached paragraph on page 150. Fullgraff's athletic memberships are again listed, and is listed as a Salesman connected to American Lithographic. His house address matches the previous link. He was born in 1851 (I think this means he is probably the man in a database here, who died in 1943 in Manhattan:
https://www.ancientfaces.com/person/...1943/110083839)
https://www.google.com/books/edition...sec=frontcover
A salesman for American Lithographic, detailing production for Old Masters, and working for Brett securing contracts, with at least the last 2 being at the same exact time. I am now pretty positive these companies were indeed shadow subsidiaries of American Lithographic, multiple locations but not really multiple independent businesses printing the T cards. It makes sense for 1910.