Tom Martin suggested that possibly Mavic had bought up and taken over Mafac in the 80s. I don't think so, but I'm not certain. The big take-over by Mavic was of the failing Simplex company with whom Mavic had had some collaboration over the years eg the retrofriction gear levers. Mavic's factories were based at the time in Annecy, a very expensive city, and the company was looking to expand. Simplex was based not too far away near Dijon in new extensive buildings. Clearly they had all the know-how to produce gears, but at that time, not the designs. Whether the later models of Mavic gears were produced by Simplex or on ex-Simplex machines I don't know, but they were obvoiusly not CNC machined in the same fashion as the early Mavic ones.
The take-over/relationship did not last long and Simplex joined up with a couple of other steadily failing companies such as Pelissier to form the short-lived Stratec group.
If only Simplex gad not used so much black Delrin plastic they might still have been in business. Norris Lockley.