OK, so I had a Titan laying around. I also had a Trieste laying around that I was very hesitant to cannibalize. So, the inner engineer in me went to work. My approach to this was to copy a USD second stage holder and then use the lever & supports from regs that I'd put HPR's on. In my layout I figured I needed three holes in the second stage holder and had to have one pointed at the horn. For cans I got a set of Mistral cans from Rob and used a 2-1/4" knockout punch to open up the front to accept the Titan/Trieste body. So here we go:
Here is the second stage holder next to an Aquamaster second stage holder. Note the clocking of the outlet holes is different.
Here is the second stage holder installed in the titan body with a seat holder from an Aquamaster. Holes had to be drilled & tapped in the body to be able to fasten the lever supports to the body. Layout is important - I copied the geometry from an Aquamaster body.
And Here is the body installed in the rechromed Mistral can, cut out to accept it. I oriented the holes to put one pointing at the side of the outlet horn. I've dived this and it works quite well. Note that I used a Conshelf adjustable seat holder with nylon insert locknut in the final install, this is the same as from the HPR and allows easy adjustment. The lever height is such that it uses a single stage diaphragm instead of a two stage one. That was one of the first things I looked at, and the Titan/Trieste forging has a higher deck height than the Aquamaster body. It all worked out quite well.