Well what do do you know, I actually did a "Chuck" and trolled the archives (!) and Eric Elman answered my query back in 2003!
Seems these are Normandy Sports hubs and have no business at all on a Peugeot PX-10.
So the hunt for a pair of Mavic Monthlery rims c. 1969-70 continues.
My apologies to the List for wasting everyone's time.
Check the archives, check the archives, check the archives
Peter Kohler