The Ozark #255 is a Fry pump kit that looks a LOT like the pump in your picture (although I think that one is actually an old Erie.) According to the 2006 price list that I have, 0255 is a Derby & Conoco kit.
It looks a lot like this:
Ozark 252-256 are the Fry glass bowl style, and 257-263 are the Tokheim art deco style.
Okay, now that I look at it, the ones that say they are Tokheim 850's (according to the picture) actually seem to be Wayne model 60's.
I think the 255 is probably the one you want as long as the logo is of the same era.