want to install open sights from scope mount
If you mean you want to mount the rear sight on the scope rail, the only sights I'm aware of are peep sights, XS and NECG makes sights that mount on Weaver bases. The problem you'll find with them is they require a very tall front sight, they're also expen$ive.
http://www.xssights.com/store/rifle.htmlhttp://www.newenglandcustomgun.com/If you want to mount a rear sight where the scope rail mounts, again you're pretty much limited to peep sights, but a couple exceptions are the Smith Long Range ladder sight which has a buckhorn and a flip up ladder peep, but it too isn't cheap, you can see it and other peep sights in the FAQs link
Peep and Firesights.
Another option if you can find one is a 30-40 Krag sight, I think there's a link to it in the FAQs too.
Other that those, you'll need to have the barrel drilled and tapped for the rear sight as well as the front sight unless you have a Superlight barrel that's already got sights, or is drilled and tapped.
Tim