Ted,
I agree with you and JohnnyH above. I had previously tracked an unknown number of backs and came up with a 70/30 ratio with Factory 649 backs being more populous. The original Net 54 post was here:
http://www.net54baseball.com/showthread.php?t=117384
Also, of the 107 T201's in my collections at present, 81 (76%) are 649 backs and 26 (24%) are Factory 30 backs. This may help explain why the Dougherty/Lord card (found with only a Factory 649 back) - although not rare - is more difficult to find.
When I had originally started to gather data on the set, I did not track back info. I was trying to figure out if all cards were equally printed; if not which ones were double printed, etc. Although, no known rarities in the set existed, it seemed some T201's did not come up for auction as frequently as others.
Initially I tracked the population of each card, but quickly realized there seemed to be a bias towards HOF'ers being more populous and the 11 minor leaguers showing up less frequently. As all T201 collectors soon realize, the set has a high frequency of miscut borders, with a bias towards the "right edge" as you are viewing the card.
I let my daughter play with the cards while I was working, and she figured out you could match the edges of the cards. It occurred to me that matching the miscuts you might be able to determine the order of cards in a print sheet which might tell which cards were single & double printed.
I won't review everything, but in sum, it appears the Cobb card was quadruple printed (showing 4 miscut edge combinations) and the minor leaguers were single printed. I have inconclusive data on the remainder, but it seems to suggest that the other HOF'ers were at least double printed and possibly triple printed. This seems to suggest that the set was printed in two sheets, if the sizes of print sheets for other sets circa 1910-11 still hold.
M Wheat