Actually there isn't that much to do. I'm paying those at Pecatonica Rifle to do everything to the barrel so that all I have to do is maybe polish it some and then brown and put on sights. The stock forearm is already inletted for the barrel and the butt stock looks like it would just need a little shaping and fitting to the action and a little inletting for the butt plate. Here' a couple pictures of the kit.You handy enough and willing to spend the time to put the kit together? Depending on you, it might take a year or more to do the kit.
I am leaning more towards the Underhammer kit, .50cal 1X36" Green Mountain barrel. I think once it's finished, if I do my part, it will be a $800+ MLI would go for the underhammer. I like mine better than my Dad's Great Plains Rifle. But it was an adventure to make. I like an adventure. I also like take-down rifles and rifles with interchangeable barrels.
The under-hammer design is old too from the early 1800's. There were even under-hammer flintlocks too. That would be something to try some day.