I'll get some pics up as soon as I'm allowed.
I agree that COCOE's truck is a big project, I wouldn't have the confidence to attempt a project like that. I worry about basic body work, mating two cabs is way beyond my comfort zone. Luckily my sheet metal is pretty good and shouldn't require too much work.
Measuring the P20 chasis I have, it looks like it won't take too much fabrication to mount the cab to it. It's a 3/4 ton single rear wheel configuration, but I have a C30 rolling chassis that I may swap the dually front hubs and rear axle from to make the COE a dually. I'll have to get the cab mounted and figure out a bed before I decide. I'm thinking about a stepside pickup type bed, or something resembling an old wrecker bed (without the booms).
The P30 donor has a fresh 350 and I think a 700R4 transmission. I have the whole truck, so will probably try to use most of the wiring harness from it (the engine has a throttle body injection so I will need the computer).