I think you can accept email without signing up for a paid membership. I can't remember what the Gold Membership cost is 20 or 30 bucks I think, there's one below that too as I recall.
For some unknown reason I had Nelly pegged as a 36. It seemed to be a quite popular caliber for the long rifles. Also what the local fella recommended. He built a 58 caliber for a friend for bear hunting, carved bears and such in the stock. It was a beauty. He showed me several where he made everything like you, but usually he said he used bought components, triggers and guards and such.
Your kind of rekindling my black powder itch. I have a couple store bought rifles a 45 and a 54 and several BP revolvers, never shot the revolvers much but shot the 54 quite a bit. Pretty accurate smoke pole for sure. I've neglected it far too long.