Dave,
That's wonderful engraving. Very clean, with nice lines.
Looking at it, I would guess that you use an air graver, is that right? If done with graver and chasing hammer, then even more wow.
I don't mean to detract from your art, or my praise of it, but to me it is almost too good. I guess it would fall in the realm of contemporary rifle making, or if the European makers made American long rifles. Your engraving is far better than the old American masters of the 18th and early 19th century.
Your intent to copy Jim Chamber's on this rifle was clearly stated, and I see why you have pushed yourself to make and engrave in this style, so I guess I've answered my own question here.
I wonder, at your skill level, have you considered doing copies of originals with all their faults?
Cheers
Chowmi