Marc and others... check out the CR website, France section and the excellent Peugeot section, in particular the PX-10 pages. Invaluable! That and the Peugeot catalogue site (see link for that) should give you a very good introduction to this wonderful machine.
But yes... c. 1972 PX-10s had Dubois plain pattern lugs instead of Nervex. I rather like the Dubois ones but many consider a PX-10 is not a PX-10 without those Nervex Professional lugs. Model names: these came later, c. 1978 or so. But US market PX-10 leaflets often called the model "Professional" as well in the late 1960s.
All this PX-10 "activity" here on the CR List is indeed gratifying! All the more so since it has inspired some of you to actively seek one out. Do. This is one of those bikes that is not as fascinating a "chat" subject as some. Nor is it one to worship on a wall. The real joy of a PX-10 is to just ride one. I spent three hours on mine today and yes Michael Toohey, she made me feel like Tom Simpson and Roger Pingeon.
Peter Kohler
Washington DC USA