If the tractor worked when it was stored, it will work again. Change the fluids, lube everything, bleed the fuel system, then install a new battery and fire it up. It will run. The 1600 is generally less desirable, I have read, and parts availability isn't reportedly as good, but it is a matter of perspective and definitions: Walmart or any auto parts store will have the fluids and oil filter you need. Air filters are readily available from Hoye, LMTC, and others. Belts are belts, and there isn't a water pump to go bad. The generator is readily convertible to an alternator, but electricity is only used to turn the starter motor, so a charging system isn't even necessary. Tires are tires. The clutch and major engine parts (bearings, pistons injectors, pump, etc) are interchangeable with the YM2000, possibly the best supported gray market tractor around, as is the hydraulic pump.
So, from my perspective, what is there to go wrong? Internal transmission gears perhaps? Physical breakage of a casting? Those would seem to pretty much end the usefulness of the tractor beyond financially feasible repair,
whatever make or model of 30 year old machine.
If it was functional or at all close, you should be able to get the machine up and working for a few hundred dollars. A wise person would budget an extra hundred or two and get the radiator professionally redone.