It doesn't really matter - you can have a very nice replica of a lock, assembled from impossible-to-do-in-the-18th-century-with-steel investment castings made directly off an 18th century lock. On the other hand, you can have a lock, forged from iron and steel, by someone that has no good idea of the shapes and nuances of an 18th century lock. Personally I'd rather have the lock that looks like an 18th century lock, than one that is made like one, but doesn't look like one. Besides, the vast majority of arms weren't made by one person anyway - those who forge welded the barrels were different then the ones who bored them, yet someone else breeched them, someone else filed them, someone else straightened them, etc. There could have been a couple dozen workers producing one lock - each with his own part of the work, and fast at that job. The stocker likely did nothing but letting the parts in. Irelevant, if you are making a gun, if your screws were turned from stock on a lathe, or swaged first. As long as you have arrived at the right shape and contour is what is important to me. If your interest is in how things are done - fine - study it, tell about it, even tell how it is done differently nowadays. After all, your wood stock - was the tree felled by axes, and the plank cut on a big sash saw?
Anyhoo, brass artillery barrels were cast, then bored - I don't know about pistol barrels. I know some were cast flat, then rolled up and soldered - which I find crazy. Don't sweat it, keep researching, and building!