If your think you may want to build a rifle from a kit or parts, dig through this guy's threads on the mzzle loading forum.
I bookmarked this one in case I ever decide correcting a Pedersoli Short Land would be a a good evening project..
..for a a few years worth of evenings.
https://www.muzzleloadingforum.com/threads/new-reworking-a-pedersoli-brown-bess.107405/