Nice double rifle, and a lot of good information above.

You really need to do Cerrosafe chamber casts before going further. Certainly if you plan to shoot this rifle. This is available from Brownell's

Remember this is a black powder rifle. Tailor your loads accordingly. You can get plenty of horsepower out of black powder equivalent loads.

The rifle would have been made to shoot paper patched bullets. You can see the rifling is somewhat similar to Henry style. Paper patched bullets are a joy to shoot and delightful to clean after, as they leave no lead or copper residue in your bore.

Curl