I have no idea if the Nervex Pro models were produced as late as 1975, but I have one of these (as repegage correctly noted) ultra-steep-angled PX10 models that is post-1973 I believe. These steep ones were the last batch built with the NervexPro lugs from all that I've seen, and have the same 76+degree frame angles as the Thevenet-era PX10LE models.

As such, this frameset will mimic a track bike on the street, harsh-riding, twitchy, but with a zeal for attacking a steeper hill in the one gear you're carrying. It is also drilled for brakes and can even run 27" tires with fenders.

It was a good-looking bike as shown complete, but only certain riders will appreciate that steep geometry, and only over certain road conditions I'd imagine.

A longer and stronger stem with quill sanded down to 22mm and with slightly wider bars would calm this bike down a bit, and would be in keeping with it's "attack that hill" mission in life.