I am assuming you are speaking of 8 lug split rims, if so i found the modern replacement for my 53 3600. These can be found used and not expensive off a Ford Econoline and the 3/4 and 1 ton stock Chevy and GMC caps will fit with spring clips.
If you are talking about 6 lug steel rims, these are everywhere in reproduction. Check out any Hot Rod type magazine, wheel vendors are out there and can put together anything you need.
