If you want a real challenge build one from scratch.
I purchased a extra fancy curly maple stock blank , L&R lock and a trigger. I tried making a trigger and could not get the look right for what I wanted so I bought one.
I made the 10ga. Blunderbuss barrel .788 bore out of a piece of water well drill rod , ram rod out of a piece of drill rod and a piece of 3/4" round rod. Blacksmithed the butt plate out of an old horse shoe rasp side plat and trigger guard out of old double cut files the ram rod thimbles are made from an old deed center from my lathe.

If I put 80 grs. of FF and 2 .760 patched ball in it and shoot it with moccasins on it slides me back a full step 10 shots of single ball and my shoulder is done for the day

I was almost unemployed and wanted a smooth bore for rendezvous.$200 in parts and about 800 hours (I kept track of the time)this was about 18 to 20 years ago. I have a pistol to match it that is not finished yet. I have at least 30 hours let to go on it and I can not seem to get the trigger guard the way I want it.

If I could figure out photobucket I would post some pictures.