A remanufactured compressor consists of this: New  front shaft seal, new
magnetic clutch/pulley, new rear valve plate, new oil, new paint. Thats it.
The unit is not opened up, and no bearings are ever replaced(there are
zillions of them inside).

Perhaps this is ok, after all most vehicles have a low pressure cut off
switch that protects the compressor when refrigerant is low. Oil inside the
compressor gets low when refrigerant gets low. It leaves the compressor and
circulates through the system( ever to return) when refrigerant level gets
low. When people recharge their system do the ever add new oil to the
compressor? Should consider doing this when recharging an older compressor.
did the person who previously owned that rebuild compressor do this?

Get a new one form Bus Depot.