Hmmmm. French (more or less) = Italian = metric. I wonder if you have set of levers pulled from a band-on set. My understanding is that those cannot be fitted to braze-on bosses
My 1981 Motobecane Team Champion was speced ( supposed to come with) all french Simplex,Spidel,ect parts. I put all Campy on it and was told " no way will the old Campy NR levers interchange or tighten down. They do both. The only lil bug was the lever didn't lay down parallel with the down tube when they were against the stops.About 10 strokes with a rifler file on each lever and they do look store bought. If a screw is a tad too long, file it down to fit, nobody but you will know!
Dickey Greer
West Monroe,La USA