That gun was proofed with powder S, and is almost certainly pre 1900, and, likely pre 1898. It is the 1894 patent version of the R model, nice enough design, but, way past it's prime. The grade marks are the old style, not seen regularly because they are very old. It was, at one time, a very nice gun. Myself, I'd use it as a wall hanger AFTER I recovered the main spring and the ejector hooks (the only parts that break with a bit of regularity on a Darne R model) but, it would be on a wall in my garage-not my house. And, I've got a crummy house.
Best,
Ted
