Erod has a point about the rebuilt engine... My car has 117k on its engine and it's still running strong. I do my oil changes, do any other regularly scheduled maintenance more than regularly (down to about 3k specifically for oil changes). High mileage engines need more care and attention than newer engines and if they haven't been taken care of then their chances of going bad increase significantly.
With that said, it's something to keep in mind about rebuilding that engine. The block itself will still have that many miles on it and could experience weakening. The internals would be fine since they would be newer but unless you switch out the block you may have issues. Granted, you aren't running boost so the chances of you blowing a block are miniscule. It is still something to consider.
Tough spot... I wouldn't get on your dad about mistreating the car though. There is no direct proof of it and wouldn't want to get you into trouble
