Well I received my tank and regulator today. I am very excited since it is a complete period set bought at the same time.
Yellow Tank Original (and only) Hydro 11-57 with original harness and perfect aqua-lung sticker.
Tank valve manufacture date 10-57
DA Aquamaster (can never opened early 1958 without hookah but with aqua master internals)
The condition of all parts is very good. It was a great find
-Ryan