There is nothing wrong with the "kits" sold by TOTW, Pecatonica River, Sitting Fox or the others who provide them.
Their parts are usually the same parts as Chambers provides if you buy a Chambers lock with the kit.
There is a reason I put the word "kit" in quotes.
As you know, there are the kits imported by Traditions or Lyman or made by Pedersoli or Uberti.
These are fully machined and inletted and usually only require some sanding, metal polishing and applying the stock and barrel finish.
An average guy can assemble and finish one of these in about 15-25 hours depending on how careful he is and whether he takes his time or rushes things.
The "kits" provided by TOTW etc are a box of rough parts.
Only the lock and set triggers are near finished and things like the holes and threads in the holes for holding the lock and trigger in place are not located or machined.
The barrel is usually threaded for the breech plug but it is not installed.
The underlugs that hold the barrel in the stock are not located or installed. Neither are the sights.
Things like the trigger guard and butt plate are rough sand castings that will need to be filed, sanded and polished.
Now, you can pay the supplier to breech the barrel, cut the sight dovetails, cut the butt for the butt plate (although you will have to do the final fitting and installing), install the barrel underlugs and do a few other similar things but basically YOU are the one that will have to do the final stock shaping and thinning, the drilling, tapping, filing, inletting, pinning, final sanding finishing and assembly of the parts.
One of these "kits" will take the average first time builder 140-180 hours of his time working on the gun.
If you feel that you can do these things with our help then go for it.
If your slow and careful you can end up with an excellent rifle that will last for hundreds of years.
Not to brag but these are some of the rifles I have made from mainly Pecatonica River "kits".
A word of warning: Building these is habit forming. I started with just one.