Dinodave,
Welcome to the Bolt
Before getting to far lets try to ID the year...as Truckerni said it's easy tell the '28 and back and the '29 and up cars and trucks just by looking at the engine. "28 and back are 4-cylinder, '29 and up are all 6-cylinders (until 1955).
You picture only shows the front half of your truck. Does it have Dual Rear Wheels? If so it's a 1930 or newer as they were a standard option starting mid-1930.
The name Capitol, National, International, Universal were all pet names given to the passenger cars. I've never seen it used when talking about trucks. Trucks were always refered to by their Series letters, LQ, LR, LS, NA, MA etc.
Another option for removing the rust is to have your parts dipped in a chemical bath that takes it back to bare metal. Check to see who does it in your local area, here it's called Chem-Strip.
The engine serial number should be located on a machined surface near the distributor and will be machined stamped into the block. The engine casting number will also help ID the year...what's that number?
There are no direct replacement tubeless tires or rims for your 20" tube type tires. Chevrolet first used tubeless tires on the trucks in 1956 and they are mounted on 22.5" rims. Sand blast your rims and paint them and install new tires, flaps and tubes, the rims you have are not the widow makers, but should be mounted by a tire professional if you don't know how to safely handle them.
Check out Coker Tires...
https://www.cokertire.com/firestone-650-20-truck-tread.htmlAdd some more pictures to the page Peggy set up for you and get all of the engine casting numbers and post them here...we can help!
Mike B
