First of all, congrats on a successful build. Secondly, you did a great job re-purposing parts, making a leftie from a rightie stock.
There are several things that stand out to me that you could have done differently.
One is that the front extension of the guard should be inlet into the wood so that only the facets are above the wood.
Second, there is a flat area ahead of the guard, and that should be gently rounded. There should be no flat spot at all here.
Third, the panels around the lock are bigger than I like to see. The opposite side from the lock has the same issue.
One thing that really helps so much is to visit a builder or a gun shop that carries other muzzleloaders, and look at how the items above are handled.
I live in a muzzleloader vacuum in upstate NY, and hadn't seen a decent muzzleloader, much less originals, until I had gone to Dixon's Gunmaker's Fair. That has been, and continues to be, an eye-opening experience for me.
All in all, this is a good rifle, one that you can be proud of. I like your creativity and your 'can do' attitude. Thank you for posting!
Tom