Hello Dusty,
I'm not sure if this will work with your tractor but might be worth a try? The person I bought my tractor from over 11 years ago used to buy up many orange compact tractors fix them to resale,
many of them would have the clutch disc frozzen to the pressure plate just as yours has from setting up for extended period of time, when I bought my kubota the clutch disc was stuck as well, He showed me the procedure he used to free them up, there is an inspection cover on one side of the bellhousing he would spray hot steam from a pressure washer into the hole in the area of where the disc and pressure plate are sandwich together while having someone bump the engine over every couple minutes while working the clutch, while the rear of the tractor up on jack stands, after about 20 minutes of putting steam to the clutch it did in fact free up,
He said sometimes it wouldn't completly free up and he would then have to go to step 2-- pull it a few feet to finish the job in order to free it up, he said this technigue work 9 out of 10 times, I realize this actually doesn't do much as far as resurfacing the pressure plate but I guess it does save from having to split the tractor to get to the clutch, My tractor last quite a long time after doing this, I only had one time where it might had been having clutch problem, but it was do to it getting hot from eccessive useof a bush for several hours, once it cooled the clutch stuck once again I simply turn the engine over and it free back up was back to business s usual,