WINCHESTER ACCESSORIES NO FURTHER A MYSTERY

I’m in a little town 40min South of Denver, CO. I joined largely to find out more details on my father’s 1959 Design 70 .300 H&H Magnum. I don’t hunt, so I’ve only taken it target shooting thus far.I even now haven't had it on the range. This is definitely on my temporary to do checklist. It's a Lyman peep sight on the side. That same cousi