More work done on the tractor!
Turns out I am NOT using those hub adapters. They would have still needed modification to use anyways.
The one set of rims was the right size, except that it was for a 3/4 drive shaft instead of a 1".
My friend Rich has a BIG lathe, that he can chuck an entire wheel in. I bought one foot of steel tube with a 1" INTERIOR diameter and gave it to Rich. He put the rims in the lathe and ran a whole saw through to cut out the original 3/4 pipe.
Turns out the whole saw was the EXACT SAME diameter as the outside of the 1" ID pipe! He just slid a 6 inch chunk of pipe into each rim and welded it in! (OK - he actually drilled the cross-pin hole first, and threw a coat of white paint on afterwards as well! Thanks Rich!)
I went to the auto parts store and bought a "four-in-one" air valve tool. It's for cleaning up threads on valves, but since it can screw onto the threads, it gave me something to hang on to to pull the new valve stem through the rim. It worked great, and was well worth the $2.09 I spent on it!
After that, it was a bit of wrestling to get the new tires on the rims. I had never done that before, but lubricating the tire and rim with soapy water seemed to help. Then, a bit of air from the compressor, and POOF! New ElecTrak wheels!
I did some more work polishing up the drive axles on the transmission. I also reamed out the inside of the rims with my 1" spade drill bit. Then I lubricated/protected the axles with some anti-seize metal grease, and slid on the new wheels.
The old rim was used as a stand. Almost 40 years old, and they are still making the same tread pattern!
I hope to be the guy who pulls these rims off to replace the tires 30 to 40 years from now!
(Nah, on second though, my grandkid can do it!
)