Not sure about the barrel. I don't think it's a factory S&W barrel, hopefully it's a quality aftermarket replacement and not a garage fabrication. Good rifling?

I'm not too familiar with the early 39's and haven't seen that matte finish on a magazine before. I know the older magazines used a metal, X-shaped follower, and the newer ones were black plastic. If you post pics of the followers another member may have something to add.