Looking at your pic, I'd say tires have about 30% left...good for another 5+ years!... and rims appear to only be rusted. I'd:
Remove tire, sandblast or wire brush rim to remove rust, loose paint, etc.
Treat any rusted areas with a rust converter... Extend or similar.
2 coats of primer on outside and 4+ HEAVY coats on inside.
Allow to thoroughly dry then 2 coats yellow and allow to thoroughly dry.
Replace/install tube, mount tire, add air, and...happy farming! Bob