[motto]

I can't imagine a civilian operator installing the blackout marker light on the mudguard This and the headlight switch having what appears to be a cross bolt lock which would mean the switch was military may give a clue to the origins of the vehicle. The cab is definitely North American, the front bumper is of the heavy military style and the chassis has the riveted plate reinforcement on the side rail common on military trucks but maybe not exclusively so.
Is there a tow hitch on the truck?
Also could you post a photo of a front wheel bearing cover? If it is a pressed steel cup, that is indicative of a light axle, if it is a domed plate held on with six bolts it is a heavy axle.

David