I think it goes like this:
MF = Manufrance = Manufacture d'Armes et de Cycles de Saint-Étienne. I think they were a manufacturer or combine that distributed a variety of products from about 1905 - 1980, including bikes, guns (some of their shotguns are collectible) and cameras(!). I had a Manufrance bike in the '70s, with Simplex ders and Mafac brakes.
From the photos of these hubs they might have an internal freewheel mech, like modern-day rear hubs and Baylis Wiley before them. My BW freehub has three cogs, but I bet one could put 4 on it with some experimenting (Frankenhub?). This MF hub looks to have two cogs.
Dave Ross Portola Valley, CA USA
Joe Bunik wrote:
"These certainly seem unusual. Any guess as to whether this is a double-fixed + freewheel hub, or if there are three freewheels here? Who were MF? Item 330004280349."