Here is some info on it. http://www.amderringer.com/das.html I noticed it has the exact sizes so that gives you measurements to go off considering the prop is obviously based off that gun. I know there are a few differences on the barrel and the rest is probably another gun or custom, but still.
Nice work on yours, it looks great. I was thinking, maybe you could get one of those gun lighters and install it in the model somehow, so it does look like a welding torch