Being a fan of the Scubapro MK V/109 combination, I decided to create a MK I/109 version using parts from various regs. The MK I differed from the MK 5 in only one regard, that being a single LP port originating from the end of the piston cap. The MK 5 originally had a two LP port swivel. This particular first stage body was an early version that used a retaining clip to hold the swivel. It also had the "thin" yoke and screw that were designed for 2,250-2,500psi cylinders. I believe that this particular model sold from the late 60s to early 70s.
The piston cap came from a very rough first stage, and as you can see from the photo, was badly in need of some TLC from our own Dave Ali. The resident Scubapro historian, Luis, provided me with the necessary internal parts. Thanks, again, guys for the awesome help.
Anyway, as you can see, the finished project looks pretty darn nice. The IP is a rock solid 135PSI with a cylinder pressure of 2,300PSI. A test dive is in order as soon as I can start diving in a wet suit.