I acquired & rebuildt a couple Pro Flex bikes about 10 years ago.  First one was very easy.  It was a Reptile, said so right on it.   

This second bike is older (cantilever brakes) & has a pretty conventional frame.  What's different is the rear suspension.  I've never seen a pic of a similar one anywhere.  Note the stays mount half way down the swing arm rather than fully to the rear.  The rear "shock" also mounts away from the frame & utilizes a damper (oil free) above it.  Who knows what is actually original but it has almost a full XT group w/LX crankset.  This bare aluminum frame was covered with race stickers.  Only the head badge remains.  Anything you could tell me would be appreciated.  Seems to be rare, even by Pro Flex standards.

It's a 954, like this one.

I think a Vector is the correct original fork for this bike.....

Man that ancient rear shock looks goofy. Interesting, though, that Pro Flex started with the "more correct" positioning of the single-pivot mount in front of the crankset, then moved it to the rear in 1995, then moved it back to the front in 1997.