Because I'm old my eyes aren't great anymore. I would love to scope all my old rifles for this reason. But, I just can't do that to a great old rifle that is unmolested. I have compromised by getting bolt mounted peep sights mounted on spare cocking pieces. Keeping the original cocking piece safe for remount if needed. This allows the rifle to be put back to original condition with no permanent consequences.

The peep is barely visible on the 1913 Mauser.