Here's a few more photos, the swivel stop was installed professionally by the looks of it. May have been added later by a smith. Another thing I noticed was a couple of brass colored soldering spots along the bottom of the barrel, maybe brass housing for a cleaning rod. Also, there seems to be a letter 'B' stamped on the top of the barrel close to the chamber, it's not clean or straight so I doubt it's factory. I appreciate all the support on this, let me know what you guys think.