Thanks OT
I will take a close look the next time I have access to the barrel - which will probably be when I am ready to start the build. The curiosity regarding origin set in after the owner returned home with the parts and I did not have the foresight to take pics. The following is based on memory, which tends to be a chancy thing these days.
I recall the breech section being octagon, followed by a single wide wedding band, followed by a shorter 16-sided section, followed by a narrow triple (?) wedding band and then the round section. I would NOT put money on that
. The wide wedding band might be a figment of my imagination. I was somewhat concerned about the lack of markings and suspected it just MIGHT be an import.
One thing that really impressed me is that the contour of the forward wedding band is actually in the barrel inlet. I will be surprised if any of that - other than the upper edges - survives final inletting. There is also the possibility the barrel will need to be set back.