Find a "rendezvous" in your area. You can learn a lot from those guys and its a lot of fun.
If you go with the Hawkins/mountain rifle, you'll find yourself making your own powder horn, hunting bag, patch knife, etc.
BTW, those crescent shaped buttplates are held against the arm and not the shoulder.
Vigilantibus et non dormientibus jura subveniunt. Molon Labe!