I have a Bell (hands above head) which I think is pretty scarce. There's a scan here:
http://www.net54baseball.com/showthread.php?t=178465
I haven't noticed any others in my searches which makes me think some of the OM backs might give you problems. The Bell card is one of my favorites and I have several others with various backs. I don't think I'm ready to part with it yet but depending on how your quest develops I might be swayed to contribute. Good luck!