Last summer I noticed the tires had dry-rotted and pumped them back up till I finished mowing, then put the tractor in the barn and didn't think about it till this year. This little tractor gets run about 100 hours a season.

This morning I had to put tires on it. Firestone 8.3-24 R1 offroad/ag tires.
There are hundreds of thousands of these little tractors all over the US. They all use the same engine, the small diesel from Mitsubishi. In either the two or three cylinder variation, this engine powers IH, Case, John Deere and probably a couple of other brands. If it is a small diesel tractor, you probably have a Mitsubishi engine.
The tires never wear out on these tractors. They finally just dry-rot off the rims. I had a heck of a time finding two tires in this area, simply because there isn't much demand for them. I actually started last week trying to find some tires that didn't demand a king's ransom to buy and mount.
I got it done at a local place. I took the tractor off the trailer and sat in the shade swapping jokes and smokes with the tire mechanic, a guy about my age. He was kind of pissed, because, in his words, "The boss ran off all the other help and now he is on my case because he's behind. If you don't mind waiting, I'll change those tires right now, but I ain't getting in any hurry."
I propped up on a skidder tire and we talked while he worked. About half-way through the job, the boss came out and asked him to change one steering tire on a Kenworth tractor. He looked at me, and I shrugged my shoulders. He jacked that tire off the ground and changed it with the rim still on the truck, using tire irons. I offered the comment that it looked like he had done that a couple of times. He told me that he had been changing big tires for 29 years and that it was easier to change the tire on the truck than taking it off and putting it on the machine. In twenty minutes he was through, and got back to working on my tractor.
All told, with the jokes and the coke and everything, it took about two hours to put the tires on that tractor. I really enjoyed sitting and talking to a man who obviously understood his work.