80 Cart Wheel and Tires

If your post is not deemed to be in the proper forum it may be moved. Don't be concerned about that.
The wheel(s) pictured look pretty rough and at least the one will probably need to be replaced, should you wish to do so.
What to do and where to go and how expensive, etc. regarding that = I don't know for sure and would have to do some research myself.

Might still be available from Deere, but would be pricey. Watch the Classifieds section here.
Unless this is a "look don't touch" restoration, I'd just replace wheels/tires with aftermarket ones...paint the wheels if necessary.

That wheel does look pretty rough, but nothing that can't be fixed easily. I worked at a tire shop and its AMAZING how much abuse a steel wheel can take and still be usable. Rip that stem out, hit it with a good wire wheel, weld up those holes, find a patch for that missing bit of the bead to weld in and you'll be good to go. Grab some tire seal to slather around that bead. It'll hold. If nothing else, throw an inner tube in there and call it good.

I have a ugly duck wheel just like it. Have someone cut the rusty part off and weld on the same amount from a good set of 8" front wheels. Weld bead inside the rim. I bought a 1'' bolt and cut the rusty part off in a lathe.