After a week of additional research, I don't have much additional information to report, but here is what I know:
- The OTR website is lacking any technical information, and phone calls have not been returned, so I haven't been able to get tire specs from them.
- Mulitple Kubota dealers in this area have not been of much help either, other than to look up the Kubota part number for the tire. Depending on the dealer, a factory replacement is in the $200-$250 range.
- I don't have the factory service manual, so I can't determine what the factory front tire specs should be....so I can't determine if I can go to the Firestone radial that has been discussed in this thread.
- There is one online site (Ken Jones tire) that has the factory 4 ply OTR 7.2x16 tire for $149, but it is out of stock. They also have an 8 ply of the same tire that is in stock, but price is not listed.
So at this point, I think that I will order a pair of those tomorrow and will hopefully be done with this. I'm tired of my tractor sitting out on the sidelines...