Wing made from PVC pipe.

[Rich Keller]

Nice looking back plate btw:

That is a commercial diving harness that you can usually find used on ebay for between $25-75. I did eventually attach a wing and cam bands to it to use for a travel BCD.

 

[NAM001]

The ones i am familiar with of that era had a fill valve, no bladder and the back of the tube was partially capped off. to fill you used a valve and to vent you took a down angle to let the air run out of the back. boy this takes me back to electrolung 1 and 2

I'd love to see it too (just the "enginerd" in me). My suspicion is that they were vented/open bottom, with a internal bladder that is connected to a "typical" inflator.