Bob: You do need to change oil if it's milky. Panel fan's clue may be "dip stick milky, not the oil in pan". Hope you luck out and it's a breather thing. Does not seem to make sense that a new motor would have condensation. (in our dry state of AZ). Does make sense it was screwed up by builder. Hope it was a blocked draft tube or something minor.

Be careful not to throw too much more money on a tear down and magnaflux and etc. Those motors are not that expensive. If they find something , then more money! Since you can't take it back you have to think differently about this. Buy a motor for $300-$500 with good compression and hear it run and check the oil. Drop it right in and go. Lots of parts off your motor still good to use.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn