I have a South Bend Heavy 10 with the Quick change gearbox. I've had 51 year relationship with it. I trained on this very lathe in 1968 -1971 in High school and bought it from the school in 1973 when they were getting new machines. Came with every thing, stand, motor, 4 jaw, 3 jaw, taper attachment, all for the scrap price of $100. Tried to buy them all but they would only let me have one. It's a 1941 or 1942 and still holds any tolerance I care to hold. I've made a lot of engines on it. The only thing I replaced was the forward - reverse switch. After years of use in the fwd direction the hold latch was worn. I just crossed the wires in the switch ( the reverse direction is almost never used) and back in business. I wouldn't be afraid of an old machine, remember "All new machines are made on old machines."
Many years ago I was in a shop that made the steam trains for Disney land and Disney world. They had a a large lathe that was made in 1890. They used it for turning 24" driver wheels. I asked the operator what kind of tolerance he was holding with it. He proudly said" .0005". Can't ask for much more.
Besides old machines have a lot of parts and tooling available at decent prices!
Jim G