Mag Craft:
My suggestion would be to have the tires de-mounted, and then clean up the inside of the rims.
It is likely that they will need to be sandblasted, and they should then get two coats of two part epoxy paint.
It may not be such a good idea to use the old tubes either. You can buy tubes (on line) very cheaply.
If the rims are badly pitted it might be cost effective to buy new (on line) aftermarket rims. They will cost about $150 each (plus shipping).
The first place rust will usually show up is around the valve stem.
If you don't have any rust there yet, you very likely can still save your rims.
If still solid, your rims will last forever, if you get that **** calcium chloride out of there, (and get rid of the current rust), plus epoxy coat.
I am amazed that some people STILL use calcium chloride.
I believe that most (if not all) new tractor dealers refuse to use it.
Tire stores are happy to sell it though, because they know that in not too many years you will be new rim business for them.