How can I repair a Palruf roof?
I've never dealt with the stuff, but I'd say if it's near the ridge line, remove whatever you have as a ridge cap, place the patch on top of the hole large enough to tuck under the ridge cap, and then replace the ridge cap.

If it's lower down, I think I'd patch it from the inside, and use silicone or some other sealant from above.

As for adhesives, my normal stand-by for this sort of thing (waterproof, gluing sheets together) is DAP contact cement, but the two pieces might not mate together well enough for that.  You could probably use a mastic, such as the roof cement they sell in caulk-gun tubes for dealing with flashing, although, it tends to be pretty ugly, so you might want to just use it to afix it, and then use silicone around the edges.  (I don't know if silicone would hold well enough for this on its own)