update.
 

My real end oil leak has stopped. I dont know what happened. the first 500 miles after having rear worked on oil was still coming out of vent. now finally after a full week of work, 1700 miles. not a drop. bone dry on rear, especially near the vent.

Probably just oil that was still hanging out near the vent, worked its way out. The repair probably did fix it.

Oil doesn't "hang out" near the vent. He had it re-bearinged so all the oil would have been drained and the housing wiped clean. Only thing that will make oil come out of the vent is pressure. That's why the vent is there to begin with. Some vent a little or a lot, some not at all and some intermittent. There's so many variables as to when and why the pressure builds up enough to vent it's not even worth trying to figure out. Best thing you can do is periodically check to make sure the vent is clear so it can work as it should and not worry about it.