Gary, that should make a good first kit for you. I think the problem with trying to replace the furniture is that nothing will fit existing inlets that are there. It will be pretty difficult, IMO, to change that unless you can "safely" take enough wood off to re-inlet new parts. If I were you, I would leave the brass and focus on working on the stock architecture as much as possible to "lean it down" while still having your parts fit.
This is not a traditions kit like you have, but a few years ago I took my stock Pedersoli Frontier and did a complete rework on it, including converting it from percussion to flint, having the barrel cut and rebored, adding and changing furniture, and massively reshaping the stock. I made a Flickr album of the entire process start to finish. This may give you ideas of what can be done with a production gun (same as a production kit) to alter it's appearance dramatically. I'm not recommending anyone do all I did to this gun (I went a little crazy) but it is a good list of ideas of what things can be done to most production kits/guns to perhaps make them look "more traditional."
Here is the thread I had on the Gunbuilding forum at the time, and below that a current link to my Flickr album. If you double click any of the pictures, it will show just that picture and below it comments I made about the picture, what I was doing, etc.
https://www.muzzleloadingforum.com/threads/pedersoli-frontier-rebuild-underway.98605/
https://www.flickr.com/photos/100435142@N08/albums/72157650877821348