I can probably get hold of the document for assembly. That will give dimensions & weights of all the parts of the truck as they come from the factory. As they say in the best manuals "disassembly is the reverse of assembly" so all you have to figure out is what size and/or weight of pieces your want to reduce it down to. You may not want or need to get all the way back to the component parts. The chassis was originally shipped with the complete rear axle removed but with engine/converter/radiator, steering linkage and RH hydraulic tank all installed, plus the rear suspensions are left hanging off the chassis and secured with ratchet straps.
Basically what goes loose is the complete rear axle (diff housing complete with 2 final drives, diff, transmisssion, & dog bone), 6 wheel rim assemblies, 2 front suspensions, 2 cab supports, cab, steering hydraulic tank, & fuel tank. Then there will be a pallet with all the steps, walkways, & handrails, and a couple of packing cases with stuff like exhaust extensions, hydraulic hoses, mirrors, nuts & bolts, etc.