Doc, I think that old scopes on old guns are great. I have an old Kolmorgen scope on a first run Remington 760. It's great. But it doesn't add value to the gun. A mount like yours is drilled and tapped into the side of the receiver........which reduces the value and only allows your rifle to be a shooter. Decent shooter 99's will get $400 any day.
I am picky about my 99's. I only like models with the schnoble forearm.....models E, G, early F, EG...... a 99 snob!
Brian
BTW, I was talking about the flip up rear site, not the scope mounts. That site is either not original, or factory original but not normal.