Thanks Ole. I swear I had already tried that--as I read your response was trying the same technique on my Recomar 33 with the same problem, so not quite sure why I wouldn't have on the other camera. Problem solved. Now onto the Recomar...I can get it back on the rails by extending via the focus knob, but am unable to keep it on the rails if i want to close the camera because the shift knob hits the bracket on the right side, and it won't turn far enough to get the standard centered (red and white dots won't meet up). Any tips on that?

As for the mystery camera, here is some more info:

Kodak 9x12 holders (Pat. 1,933,823) do not fit the camera.
Neither does an Ica ground glass back.
My Recomar Kodachrome adapter does, however, fit, albeit somewhat grudgingly.
The holders that do fit measure ~95mm wide, with a ~2mm lip and triangular point/guide nub at the top.

Thanks again for your help.