Oshawa it is. I didn't check the tag, but the Regina GM plant stopped civilian production in 1941 and never resumed after the war.
Metal is like the day it was made and measured .250" (+/- a few thou.) in a few places with my Starrett dial caliper making sure not to measure any burr that might be present on the edge of the metal. I've worked with steel, brass, bronze, copper, aluminum, and stainless steel for the last 30 years, so am quite familiar with measuring material. But, out of curiosity I'll check it again next time I visit the truck in storage. The heavier gauge frame would make sense if the auxiliary springs were factory installed rather then installed after delivery to the dealer. However the auxiliary springs do appear to be factory installed as the angle stops on the frame for the helper springs have been cut on an iron worker rather then by saw or torch. Also the angles are bolted to the frame rather then welded, which I'm sure would be the attachment method of choice for an aftermarket installation.
My GVWR is only 6700Lbs. I would have thought it would be more with the heavier frame and springs. Mind you, that still leaves somewhere around 3000Lb rated capacity.
