Looking at the rifling from here the twist says its made for a conical. If the twist is something like 1:50- 1.60 its conical for sure. A roundball twist is often 1:71 or more.
The stock does look like a re-done job but performed Par Excellence.
To get that gun here shoot again will take some technic. Maybe old 10bore paperhulls can be found or a custom-option is required.