Hi,
I think I picked up an early DA Aquamaster.
Unlike the others I've had this one:
- Has no serial number,
- Has a body that looks like a previous model 2 stage,
- No hookah or even a stub,
- Extra tapped holes in body,
- The demand lever tabs appear to have never been bent,
- The 1st stage adjustment nut was peened.
(I'd upload files but there's an error.)