The parts lists describe two bumper profiles - with straight and tapered inner faces. The earlier (to some time in 1940) is described as straight profile and the later as tapered (standard rolled steel channel). I believe the constant thickness, as on Paul's truck is reasonable for the age of the truck.
The engine has features that are consistent with a 216 but are also believable for the "splash oiled" 235 used in some US Army Chevrolets of the period. There are many discussions about engine identification on
www.stovebolt.com