If new valvestems and a good cleaning would remove the rust, yes. It looks to me like the rims have a "rust stain" from the valvestem rather than a rusted rim.Interesting.
So would you just have them replace the valve stems and go with the second tractor (after fixing the rusty bits)?
For the record here, we're the ones owning this. Its our tech who screwed up the bolts, and largly us stepping up to the plate with some good solutions. I don't mind our name being attached to this.Thanks to MrWhippy for really trying to keep things from getting ugly as often happens when these things end up online.