Posted By:
JimBTed said,
"My feeling is that the 150-only cards are very unique in the T206 issue. In all likelihood, these 12 (or so) cards
were the very 1st cards printed when T206 production was started up in 1909.
Therefore, Mr. Wagner would have been on a strip (or panel) adjoined with some of these other 11 cards that
I have displayed here (that is if this 5-card strip was an actual production, or even prototype piece)."
Ted,
I don't think there is any compelling evidence to support your feeling. It is just as likely that those were simply the 12 that were discontinued in the second run (350 series) for some currently unknown reason, such as potentially needing to drop 12 due to space limitations on the sheets of the 350 series.
Ted said,
"And Jim, regarding Plank....if you recall, some months ago I theorized that the discontinuance of the T206 Plank card
was possibly the result of the American Caramel Company's "exclusive right" to portray Eddie Plank; and, most of
Connie Mack's Phila. A's players (ca. 1908-09)."
I don't want to debate the appearance of the Plank in the 350 series again. It is really peripheral to the discussion at hand anyway.
"In the 1st Series of T206's, Plank and Wagner are only found with Piedmont 150 or Sweet Cap 150 Fac. 25 backs,
and that's proof enough for me that they were both printed on the same sheets. "
No argument here. I am not convinced, but I see no compelling reason to presume otherwise. I would even say it is likely the case given the similar quanties of each, etc.
Interesting discussion.
JimB
Edited to spell peripheral correctly per Barry's correction. Thanks Barry. 
Spelling has never been my thing.