What you’re showing is the stamped sliding rear peep version. The milled version is somewhat different, with a different adjustment knob.Later replaced with the adjustable rear peep:
View attachment 1135730
There's a stamped metal version of the sliding rear peep too.
If you wanted to replace the sights you can do that and still go back to what Gpa did. The front should be pinned in place and slide off the end of the barrel and the rear slides into the dovetailI have thought about those sights for years. I don't want to destroy something my grandpa did. Money can't replace memories.