Actually I need to change the above message. I tried one here at the house (balun) and it does seem to provide isolation, the thing is that at the shop all I had were the small stubby type that had screw down terminals on it just like the one on the right in your drawing and they all metered full continuity between the shield and one of the screw down terminals. But I have one here at the house like the one on the left in your drawing that has a tube chamber for the transformer windings and it does seem to have isolation.

So I'll give that a try.

Let me know any other experiences you all had
Jeff