Used to have a 1948 Farmall Cub. 8hp. I did everything with it- gravel, snow, garden plow, harrow, sickle bar mower. When I got it the oil was like tar. I rebuilt the carburetor, replaced two batteries (6v), two front tires, spark plugs, hydraulic oil (had hydraulics). and the magneto, and coil. The clutch gave up the ghost and I sold it. The engine was strong. I don't know how many owners it had had, but except for regular maintenance, I didn't see it ever wearing out. It put modern cars/pu's to shame for longevity.
I have a NH TC30 now with 950 hr. I'm the 3rd owner and 300 of its hours are mine. I don't expect the tractor to ever wear out. It is rugged and engineered to be solid. I keep up with the maintenance. It may not look pretty, but it runs well.