FOR SURE, steel rims with 3" high bolt on lugs. But back then wide open cruise was about walking speed.You know, at one time all tractors had flat proof tires.
With pneumatic tires the true "wheels of modern civilization", I don't think "flat proof" has a real foot to stand on. If I worked in a land fill, I may think the flat proof technology a true god send.
These are not "flat proof" that you are referring to but pretty darn near close. I purchased a set of fronts for my 4610 SU from them several years ago and have yet to flat one brush hogging. I don't know if they carry sizes for smaller tractors but I have been extremely pleased with the results.
Gensco Tire. Home of the no flat aircraft tire.