Thanks Huck. I believe I have 3 good leads with these gentlemen. All have experience working on a falling block, breech loading gun. I have to decide the caliber since the original is no longer made ( The rifle was probably a Gibbs /Metford .461 No2, a propriety Black powder round. It would have had Metfords accelerated twist segmental rifling and would have shot either 570 grain paper patched bullets or the 360 grain patched express bullet.)
I realize this has been an unusual request for the forum and appreciate the input from each of you that posted.
If anyone else has a thought, please speak up. These guys are running between 10 and 18 months before my turn would come up so I have a little time yet.