Say I assemble them making no effort to conceal their nature. I’ve got a long pre-revolution fowler barrel, an early SMR stock, and an Enfield musket lock. Still a forgery?
Not guilty of forgery, but certainly guilty of bad taste!
You are offering a straw man argument because the combination you are
now describing is farcical. Initially, your proposal was: "I find an old barrel that came from a barn, a lock that came from an antique store, a battered stock I bought cheap at a gun show. With minimal fitting I assemble them into a complete rifle. Is that forgery? I don't think so."
That statement is what initiated my response, and in the general terms you preliminarily described, I could conceive of it as a forgery ***assuming*** that in the general sense that you offered your initial scenario, one would not be mixing and matching components from three distinctly different stages of arms development. Your more recent, refined scenario would (hopefully) never be considered a forgery because it wouldn't fool anyone!
I also did render a specific note above that I am not speaking in terms of legality; I am only speaking in terms of how collectors may (or may not - I surely can't speak for anyone other than myself) view the assembling of dissimilar components into a complete arm, again ***assuming*** that the components may be compatible within a historical sense.
I do not believe that we are discussing a realm wherein all is clear-cut or in black and white. Perhaps it might be so, or more so, within the legal realm, but I am offering my own opinion fwiw under the assumption that legality is not under consideration. I do agree with an above comment that 'intent' likely has a strong bearing on how a piece may be viewed, but at the same time, 'intent' is to my mind often incredibly difficult (maybe impossible?) to ascertain without a clear statement by the person whose actions may be under review.
Possibly we are talking past each other. Let me offer a scenario - and I can tell you from personal experience, it's a VERY common scenario:
A relic kentucky buttstock turns up, intact up through let's say the forearm. The lock and sideplate are missing, the barrel is missing, much of the forearm is missing. Maybe some inlays are missing if there were inlays (people had a tendency to yank silver). So now someone comes up with an antique lock to fit the mortise well enough, or maybe tweaks out a little woodwork to fit it well, makes a replacement sideplate, finds an antique barrel that fits closely, and fits and subsequently ages up a replacement forearm with pipes and yada yada yada. And it's all done well - extremely well. Now what? I'll not dip my toe into the maelstrom of debate as to whether all that $#@* should have been done in the first place. It's already done. Now what? How should it be represented, and how *will* it be represented? I would personally say that it should be represented for exactly what it is - a splinter of a buttstock with a pile of added parts! This representation, however, is in my experience fairly rare and in a number of instances I have found the owners to have no clue whatsoever until I took the piece apart. A forgery? Probably not by legal definition I suppose, but it's not something that is going to be fondly viewed. At least not by me anyway, when one considers that there is more secondary work present than original work. Again - this is a quite murky realm once "restoration" comes into play.