Jeez Dick, you must be tough on your tractors if you need that type of protection. You getting into "bumper tractor" in addition to pulling? I've got some protection also but it wasn't meant for that purpose:
Like me, I see you're not following the dominant "correct" thinking about rear rim color. I've been advised more than once that AC never used anything other than galvanized for rear rims on Bs and Cs but I believe that's too hard a position to take. I think orange was used also plus here's a showroom picture of a 1939 B with rears that appear to be black (certainly not galvanized or silver):
In any event, I much prefer the appearance of the orange ones.