That is a very worthy tractor!
I am a certified appraiser with 25+ years of appraisals in antique auto's, aircraft, all watercraft vessels of 75 feet or less, and with a specialization in modern and antique farm tractors. I have also done many garden tractor appraisals over the years.
Usually the fee for my service would be $125 for a single garden tractor appraisal but since you are new to the site I will knock $25 off the regular price as my welcome, to you.
PM me a very detailed video of the tractor including it running and operating, mowing grass, and a cold-start.
When I get the video I'll carefully study the machine to give the best possible value.
When sending payment, be sure to include an oil sample of both engine and transmission, so I can have the oils analyzed for metals or particulate material. That's the ONLY way to know what condition the main drive mechanisms are in, or if failure is imminent.
Thanks and welcome!!!