Pufferfish, There are some small parts, but other than some gearbox screws and the setscrews for shaft couplers, it's not being too fiddly yet.
Mounting these gearboxes to the inside of a smaller C-channel could have been lots of 'fun' with making filler pieces, shaft extensions and all that. So instead i notched the lower rails, folded them flat with outer face to give enough mount surface. Since original axle holes needed to go lower to fit gearboxes into frame channel, i also moved the axle shafts aft to keep an even fender gap.
Shaft coupler mounts to the modified rim halves, and the stackup still pinches tire like a beadlock.
I'd mentioned this broken power unit had no hitch, so my mig fabricated something, but it's best to not look there too long. I'll clean that up more when we get up to sandblast & painting. Original hitch had like 4 spotwelds to frame.
Yes, there is hardware missing, wrong lengths, and not using locktite yet since this isn't final assembly.