Chris,
I have posted pictures of the full run of Old Mill ads on my website,
http://www.jimonym.com
The captions on almost all the ads do indicate that there was more than one "baseball picture" in each package of cigarettes. I have seen the ad series run through the fall of 1910 in a Texas newspaper with the caption "Texas League baseball pictures" in each package. It's possible, but I'm skeptical, that T206 Southern League cards will still being distributed at that late date. I'd always taken those ads to be referring to the T210 Series 3 cards. The ads aren't clear, however, because they use the same artwork as earlier campaigns, including the same picture of a package of cigarettes with the same T206-looking card poking out the top.