I sent a link to this article to my sister, who is a forensic archaeologist. Her comment was that that the rifle certainly hadn’t been sitting out for 133 years. Probably less than half that. Wood and metal were in way too good of condition. Her guess was 1950s or 60s.
My guess would be someone in a hunting group left it and it was one of those, “I thought you had it. No, I thougth you had it.” things where they discovered hours and miles later that someone didn’t put the rifle back in the scabbard. They went back and coudn’t find it.
Grouse