Interesting that SNL G513 lists two different fifth wheels for these tractors, by Fruehauf and Dayton, the dayton type looks different to the one you have, with the fore and aft pivots on the chassis and no transverse pivot. The Fruehauf type has a one piece trailer lead on ramp which was always missing on this truck, so could have been a retrofit by the French but I have seen many Federals, Autocars and the like with the same Fruehauf style. The Dayton style has two separate ramps FMT16C734 and FMT16C735 but the SNL picture doesn't show them curiously2