Well Skeeter there are alot of fellows that could do that for you, I mean create a stock from scratch from a plank of curly maple. Some of those same fellows are so persnickety that they wouldn't be caught dead with a production gun.
So I think the fellow that you should contact is Fred Miller. He's one heck of a nice guy and will do whatever you want as long as it's in his power. He duplicates all kinds of wood products including different styles or schools of longrifles. He'll inlet the barrel, drill the ramrod hole and channel, and possibly inlet the lock...you'd just have to talk it over with him. His address is as follows:
Fred J. Miller
4025 Red Ridge Road
Mifflinburg, PA 17844
PH: 570-922-1861
Give him a call and talk your project over with you. He'll tell you what he can do and what he can't. Again, he's a real nice fellow and a neat person to know. Good luck with your endeavor.