Lots make parts, it's just whether it'll be easy to do or cheap. A gunsmith will do practically anything if he wants to and the money is right. Some gunsmiths make guns from solid stock and hand cut and file every part, others just turn screws and swap parts, it all comes down to the individual. Guns were, and still are, made by hand to a very high degree of precision all around the world. The Khyber pass is almost entirely a cottage industry, as are the phillipines illegal producers. Many can produce guns that're impossible to differentiate, and quality can be on par if the smith making them has sufficient time, knowledge and resources to do it. Both crank out tons of low quality guns because those are what are desired, but also do some very high quality guns as well. Belgium did the same in the late 1800's.