IMO,..Look to Track of the Wolf and Dixie catalogues.
You might look for John Baird's book on the Hawken Rifle.Bivens wrote a book on recreating the longrifle.Ned Roberts wrote The muzzleloading caplock rifle.
Tgere is a Foxfire book where Herschel House does a step by step building a poorboy mountain rifle.
While there are many styles of muzzleloader,a true Hawken replica is a very practical choice.
Learn the rifle Sam and Jake Hawken produced.
Then buy a barrel,a Griffin hook breech,a Siler Lock kit,wedge keys,escutcheions,a buttplate,thimbles,sights,etc
To build the lock,you will do some filing,drilling,tapping,simple torch heat treating.And you will fit a sear/hammer relationship.
You will fit a barrel channel,a simple octagon one
a crescent butt plate.
A breech plug fit up and clocking the octagon is good practice for fitting any barrel later
You will file and fit sight dovetails,solder a rib and thimbles.
If there is still Maple Magic,it works,but the old school aqua fortis method of staining and bringing out the grain of maple is fun
An L and R double set trigger bar will teach you some.
You can do a fine brown job at home.Mark Lee formula from Brownell's works.
I think building a muzzle stuffer is a fine way to learn a bunch of skills and get beautiful results,probably cheaper,using a basic set of tools.
First one I built was a .36 with a Douglas octagon barrel.It would shoot a ragged hole at 50 yds,round ball and pillow ticking.
Then I built a .40 flinter for my wife,and a true Hawken clone in .54.
I have the Cherry Corners blueprints of Mariano Medina's Hawken,which is at the museum of the fur trade in Chadron,Neb.if I recall right.
I had it on a table at a Collector show once.Some folks stopped,got all glowy eyed...ooooh!Ahhhh!Who is the maker?
"You are looking at him" I'm not famous,so then they would leave.
There was an old man at the show,a Hawken expert.He had good things to say about my work.
I'm an amateur,been building 30 yrs or so as a hobby.Springfields,Mausers,the P-14 magnum rifle..muzzle loaders,1911's,AR's,a Rolling Block...
Now,I just took an 03A3 receiver and bolt to a 1903A4 clone.
And I suggest you begin with a muzzle loader.