Time for another car unless he is willing to do a major number of work and risk.
1) Flush the radiator with water a few times, then the cheapest chemical flush, then fresh coolant. Use long life if possible since he is likely to neglect again. Do a compression test to see if the head gasket is fine, then do a cooling system pressure test to see if there is any leak.
2) New T-stat, maybe new radiator and hoses too, since he is probably going to neglect it.
3) New water pump and T-belt if not replaced by now (most likely not).
4) New transmission fluid and filter if not replaced by now (most likely not).
5) Check back and redo compression and cooling system pressure test again in a couple weeks. If pressure is ok, then it survive.
1) Flush the radiator with water a few times, then the cheapest chemical flush, then fresh coolant. Use long life if possible since he is likely to neglect again. Do a compression test to see if the head gasket is fine, then do a cooling system pressure test to see if there is any leak.
2) New T-stat, maybe new radiator and hoses too, since he is probably going to neglect it.
3) New water pump and T-belt if not replaced by now (most likely not).
4) New transmission fluid and filter if not replaced by now (most likely not).
5) Check back and redo compression and cooling system pressure test again in a couple weeks. If pressure is ok, then it survive.