Earlier models of the Auto-Up will work on the bottom loading cameras, models II, III, and IV. Those are marked "Auto-Up", and Auto-Up II" (two different focal ranges). The V and VI series cameras use Auto-Up V, which should also work on the P since the bodies are so similar. There is an Auto-Up 400 that looks like it would fit the 7.
All that said, I have used the older Auto-Ups on my P with success, but they do block the rangefinder window a little bit, which reduces the size of the focus patch.
PF