Pete, that stuff coming out the breather is one of two things:
1. Condensation from the oil pan, which I doubt.
2. Coolant from a crack.
The heads can crack some funny ways, like into the valve guide area, and let the coolant flow up onto outside of the heads while not entering the combustion chamber. It's rare, but it does happen. It would not be an overwhelming amount of coolant so it boils off easily and is sucked out the PVC.
One thing I did not remember to write was to waft you hand into that cloud of vapor. The stuff will coat the hand. Then you should be able to smell or taste the coolant. If there's no taste or smell of coolant it is probably condensation.