Thanks, y'all. I'm having problems putting my pix onto the site. Using my Nikon JPEG format, and msg says file too big. Based on JimF4M1's comments, it sounds like this carbine was rebuilt. It does indeed have the bayonet mount. Hubby says the rear sight he remembers it having is the leaf (or flip?) type, but since he lost it somewhere along the line, and it seems the carbine was rebuilt for use in Central America, might as well go with the adjustable rear site in the 30-40$ range. We're not collectors. I just like to target shoot with my Jeep friends. I didn't do too bad with no rear sight at all, but she kept kicking me in the cheek :-)