While I like the 'idea' of collecting cheap 'parts' tractors and making good whole ones, it's in the 'execution' where it'll probably fail. You need a lot of covered space to store the inventory, once you buy them as sun and rain are hard on everything, especially paint,mechanicals and rubber. You need GREAT reference books/charts/etc. to KNOW what fits what. That could be challenging for the older models,but if you're good with programming ,say with DBIII, it's doable. Time is the killer. It takes a lot of time to FIND the cheap tractors, time to dismantle, time to inventory them, time to rebuild, time to test, time to sell.