David, can you please post an enlarged pic of just the front of one of the F60B trucks in your pics from Pearsons?
I'd like to check the steering box.
There seems to be a lot of variation in the '60-cwt' chassis - for instance although all FGTs were supposed to be 3-ton chassis the ones delivered to us had the 375 steering boxes and small steering ends, yet had 20" wheels, 2 speed transfer cases and winches.
Also a large batch of 1943 F60Ls here were delivered with the light steering and 20" wheels. Our 1945 medium wheelbase ambulances had light steering and 16" wheels yet were marked as F60S on the nomenclature plates.
