Zimmerman, too, works mostly with Euro-imports to make defarbed and accurized rifle muskets, etc. His site is:[url]
http://www.edsmart.com/jz/[/url]
I don't know of an American company, other than Shiloh (Sharps rifles and carbines)or Romano (Maynard carbines), that makes CW-era guns, and neither of those makes what you want. The mass market pretty much belongs to two Euro firms and one Japanese outfit -- which, BTW, does generally good work.
There are several individual riflesmiths, however, who will assemble barrels American-made by Whitacre or Hoyt, wood by Dunlap or Jencso, and parts from wherever they may be found to craft excellent-shooting individual replicas. But those run from $1600 to $2000. If that's not too rich for your blood, let me know and I'll put you in touch with a few of them.