Putting the kit together isnt difficult in most instances. Putting it together and getting it correct is where the problems come in.
If you are seriously considering doing this, it would be good to hang out in one of the 3 major muzzleloading forums and look and ask before you go drop $750 on parts that will frustrate you to where you quit.
www.muzzleloadingforum.com
www.thetraditionalmuzzleloadingassociation.com
www.americanlongrifles.com
This is where the real muzzleloader builders hang out, and they are more than willing to give you good advice based on experience. Please dont tell those guys that you are considering using a laminated blank for a traditional flintlock rifle..........I wouldnt be able to stand the bloodbath.