On May 11, 2017, I identified in another thread a total of 50 different signed T206 Marquards out there in hobbyland (now at 57):
http://www.net54baseball.com/showthread.php?t=211673
I have therefore decided to expand the research to Larry Doyle, who I believe to have signed the next-most T206 cards. Indeed, the number of signed Doyles (11) in the 2007 Great Pittsburgh Find of Signed T206 Cards outpaced by more than double almost every other signed T206 player (there were six Snodgrasses, and - believe it or not - just two Marquards).
If you have one that is not featured here (or if you have a scan of one that is not here) can you please send it my way, or post it here? I will add it to the composite in this post and update the thread. Thanks!
Also please check out how many signed T206 Snodgrasses I've found thus far here:
http://www.net54baseball.com/showthread.php?t=255196
Updated composite (07-24-18)
Total: 26