Here’s an Autocar 2036, an off highway setup. It has a Sheepscot 20 ton rock body part #26293 one piece urethane casting. This would have been a new truck in 1954 when Autocar introduced the pit fenders as a factory option.

The right side view shows the connection for an exhaust heated body to keep the material from freezing in the winter. In the box there’s a flapper valve that directs the engine exhaust down when the body is raised.
The wheelbase is 198”, tires 12.00-24. s/n 101368