Michael, I did a fair amount of relief carving when I built muzzleloading guns, but I'm afraid those days are past.
If you note the quarter panels on the forend of my .30-40 you'll see I got the idea from studying ealier guns like your Rolling Block. As I often say, When I need something new to incorporate in a custom gunmaking, I look in the history books.

It is a marvel to see these fine single shots after struggling for so many years to develop a historic context in my work with limited research material.
You and I need to publish books, my friend!