The first vintage long rifle I ever saw or held in person was a Jacob Young rifle at a local art center exhibit called "Arms Through The Ages".
The owner was a powder horn collector/expert and was giving a talk about the art of original horns. Before his program I was looking at his stuff and mentioned I shot a TC flintlock and was thinking about trying my hand at building a PC rifle. He held out the Young rifle and said hold it, I was blown away. I was expecting an original to be somewhat crude, the fit and finish on this rifle was perfect, like one would expect from a fine English SXS shotgun today.
The rifle had been built for a wealthy lawyer in Nashville and seen little or no use, it was as pristine as if it had been built yesterday.
I knew nothing about gun building at the time, I don't remember the guy's name but he spent a lot of time with me, steered me in the right direction and gave me encouragement. He said "buy a Chambers kit, you can make money on the finished gun even if you don't do the best job putting it together". Pretty good advice but I built my first from a plank so I could learn it all from start to finish.