While doing the research on my Prime Mover III build in April 2015, I realized that what I thought was a militarized "box van" was actually exactly the same tractor I'd originally modeled a year before. Apparently this Prime Mover variant could serve in either role, pulling a trailer for large loads or with a smaller cargo module loaded directly onto the truck bed. So with that in mind I re-worked the first of my Prime Mover customs to be essentially identical. As per the last photo, the only difference between Prime Mover I and III is the inclusion of the hinged "fifth wheel" hitch.