"a groove around inside the chamber, where Mann came in for patent and always stated in the referring manuals, that this would work like a locked breech."
So that's where Seecamp got the idea!
I have CNC produced 416 stainless triggers to replace the plastic triggers on Colt Mustangs, Mustang Plus II's, MK IV Government .380's and Sig P-238's. Video on installation in Sig;http://www.youtube.com/watch?v=Jh2v_-87DRM
Also I made up a hundred Llama .32 and .380 recoil spring buttons, checkered nicely and blued.