I used Italeri's M925 5-ton frame with modified/backdated suspension and axles. For speed, I used Real Models' M54 Cab Conversion (okay) and their standard 5-ton tires (very nice). I only used the front panel and floor from Italeri's kit to base scratchbuilding efforts on to model the cargo box. Italeri's parts mimic a dropside and naturally the later version of a truck bed - where the equipment on "Easy Rider" is early, with a toolbox underneath the floor, and no dropsides. The Quad Turret is AFV Club's version from their "Nancy" model kit with some pedestal modifications and sitting on a scratchbuilt M55 Trailer. I had to raid both the AFV Club M35A2 and M49A2C Deuce kits for some components too. This is a expensive beastie so far.
I'm still working on all four subassemblies at the same time to make sure they go together properly when it comes time for the end assembly - so what you see here is a work in-progress...


Quad .50 Deuces are cool - but - the 5-ton Artillery trucks were ultimate in carrying this kind of firepower...
Gunnie