Hi Kin,
Thanks for the nice words.
As Ted says there are just the three brand/factory combos for southern leaguers.
There is a footnote, however. A handful of southern leaguer cards having the Old Mill Southern back were printed in brown ink. These cards are all hand-cut i.e. scrap. Moreover, a couple of these Brown Old Mill Southerns (Greminger comes to mind) weirdly have a red Factory 649 overstrike stamp on them. If you search the Net54 archives you will find an image of the "freak" Greminger Brown Old Mill Southern Factory 649 Overstrike card somewhere.
Scot
Here's a link:
http://www.net54baseball.com/showthread.php?t=147870