Got the Eaton 2-speed shift motor unit going back and forth. Contactors ended up being too fragged to deal with so I temporarily wired a momentary pushbutton switch alongside the plunger switch on the gearshift lever.
Select Hi-Low then press button to momentarily energize circuit. Simple and quick work around...
Bolted it up on the rear end and took it for a test drive - success! The rear end shifts.
I've found replacement contactor sets on eBay, pretty cheap too. I'll order parts and do it right soon enough.
Now to do a fluids list and budget, and deal with the front end.
I've already looked at the axle, springs, and kingpins. Looks pretty tight, might just be tires and alignment...