X2 on the peep sight. A peep sight is much better than a notch, especially as we get older and our eyes struggle to focus on front and rear sights as well as the target. You can get a large aperture peep sight for those fast shots, and it works almost as well as a scope. Just look through it without thinking about it, and your eye will automatically center the front sight.
Since you have to fix the rear sight anyway, you might as well upgrade. For extra credit, get a fiber optic front sight for those shots in dim light.