Welcome!
The old tractors are becoming fewer now, as the world's suddenly decided that all diesels are evil. Because theyre an older gen of Diseasel you can run then on veg oil without serious issue, in whatever percentage you wish (20% from memory without heavily clogged fuel filter every 5 mins) also they're torquey, can be chipped to the bhp they were supposed to have in the first place (GM detuned them because...GM) also parts arent impossible because Omegas, old 5 series and P38(?) Range Rovers used the same engine. 50mpg at 50mph, and turbo whine, what's not to like?
...sold mine and got a V6
Do it spending
wise, keep an eye out for the quality parts at the right price, as costs mount up quick, use the forum and the expertise here, it can be done. Mine was off the road for 7 years and she's been a daily driver for nearly 40k more miles now, clocked over to 213k the other day. Can be done.