WC, you forgot the best one of all:
ailes=sideclips

You're right on rectifieuse, and the guy who operates the machine is un rectifieur. But since it pretty much goes without saying that you have to grind the chokes, I think adjusting or truing them up (chokes or barrels) works better for rectifie.

Armurier/arquebusier are more or less synonyms, the latter being an older word. But "armurier" can mean someone who makes, repairs, or sells guns--all 3. "Armurerie"--one of the hardest words to pronounce in French because of all the r's--is indeed a gun shop, and that's what you'd look for in the directory if you wanted to visit gun shops in a French or Belgian city.