Looks very nice, woodwizard. That's not a metal stamp I know.
I just pulled my '52 refurb out and it has 6 small stamps on the barrel, plus 2 tiny uniform gouges that I take to be hardness tests, and none of them look like your mark. To be clear, let's not rule your picture out as a refurb stamp (possibly from some other refurb facility than my Tula went through) but if that's the
only mark on your barrel then I doubt it's been refurbed or replaced.
We would need to see a lot more photos of your nice rifle, all the markings on the wood and metal, to tell you with any assurance.
And be sure to include one with your feet. It's an old SKS board tradition.