With all respect, Beebrad, I am sure you are a nice guy, but don't quit your day job to work as a photographer.
From what little I can tell, I think it was made of bits and pieces, probably in some place like the Khyber Pass. The barrel might be from a British musket, part of the lockplate may be U.S., the trigger guard looks handmade, and the marking is the kind of thing put on in places where those funny western characters don't mean anything, so upside down, right side up, sideways, what's the difference.
It might have been made as a serious weapon at the time flintlocks were in use, but I think it was made much more recently to sell as a curio or souvenir. Any idea where it came from? I have heard that since GIs in Afghanistan are not allowed to bring or ship back any modern arms, a few have brought back that kind of thing.
Jim