These are the singlehose regs that I found until now:

Aquanaut (ca. 1968, Healthways)
Atlantis (ca. 1968, Healthways)
Nautilus (ca. 1968, Healthways)
J 200 (Kawasaki)
X 200 (Kawasaki)
Spinnaker B (GSD)
Spinnaker Pro (GSD)
M 400 (GSD)
Titan (Nemrod?)
Titan III (Starfrance)
Titan IV (Starfrance)