Have been enjoying the heck out of my new D-USA CombatMaster. The only difficulty I've had is that the heel of the frame is MIGHTY sharp, and it has worn a nice hole in the dead center of my palm. Was thinking about having it bobtailed, until I got a suggestion from a fellow on Yahoo's Detonics Collectors board that I just try installing an arched mainspring housing. After a bit of judicious grinding, I got a Brown housing to fit, and BOY has it helped. Looks stock too. Here are photos of a CombatMaster with the stock flat housing and mine with the arched housing installed. Turned out to be a great, and comparatively extremely inexpensive, fix!