Thanks for the replies and to David for all the informative posts and videos on nv. I have learned a lot from them.
Just spent about an hour in a darkened garage with this contraption on, doing all sorts of tasks and here are some things i noticed:
It has a very quick and responsive ABC. Does that indicate a C-variant tube?
The setup needs a bit of work but it's surprisingly sturdy and not too tiring to wear. I need to add some string to catch the tube in case the mount fails.
The aperture being f/1.05, the focus needs a lot of adjusting. I can see why they went with more narrow apertures with later gen 3 models even when it means loss in system gain. Also less glass means less weight.
Also those who say that a pnv-57e is as good as a pvs-5, have never looked through one.