Since this thread has kind of become the hub for T218 discussion, I'll post some of my other oddities, rarities and info here. One of the more interesting cards is a T218 M.J. McGrath with a recurring print defect/variation depending on how you define things.
When I bought the first one, I thought it was a one of a kind card, not a printing variation, but just the result of someone at the factory handling a still wet sheet before it dried. Then I found a second card, both with the same back (Mecca, Factory 30). I now think there was probably some dust/dirt/debris/something else obscuring part of the printing plate, resulting in the smudge look. I'd think there are probably several more out there, but have never seen besides the two I have. I'd love to know if any of you have this variant, or another card with the same issue.
There's a lot of oddities shared in this thread:
http://www.net54baseball.com/showthread.php?t=251642