Just an FYI, yes, you can almost always run a tube in a tubeless tire. It will decrease the chances of it going flat (adds an extra layer of rubber material for a tire that is built to be strong enough to not go flat, extra ply helps too). You can likely still run it with a rusty rim, but it might be rough on the tube and cause it to wear. A rusty rim could also keep the bead of the tubeless tire from sealing and cause it to leak air.
If you have a rim/wheel that takes a tube, then you can't run a tubeless tire on it because there is no bead lip for the tire to seal on.
I ran MonsterTires.com for 2.5 years, so I know a bit about this. Not a bad site if you are looking for tractor tires and/or rubber tracks. Local shops tend to have better prices on tires though.
