Richard,
Any chance you could show us or tell us what is stamped on the inside of the barrel lug under the extractor and or under the grips, if you happen to have the cylinder open or grips off. I don't blame you if you want to just leave it be, if it were mine I would likely hardly touch it. It's so nice I would be afraid to do anything but simply admire it. From and educational standpoint, I would like to know how the factory marked this particular gun from this period. Thanks for the pics, it's a beauty.