Absent better images, I agree with Dean that is a spectacular 4 Iron Turkish Star pattern.
Not the best pic, but something like this
Dr. Gaddy's example segment. Note the straight ribband edge welds and rod 'zipper' welds (thank you Steve Culver for 'splainin' that
)
Parker refinished by Brad Bachelder
It is unlikely that such a sophisticated pattern was originally on a c. 1860s British gun, so it may well have been rebarreled and finished in "black & white" (also atypical) at a later date. The proof marks should be interesting.
