As I mentioned in an adjacent topic I just bought a pre 10 .38 that has an adjustable rear King site and a King front site. How much if any value do these sites add? Sorry I haven't figured out how to attach pics.
I have a pre-woodsman with the king sights front back and weight tube. By far most accurate gun I own. To me king sights added to any gun increases the value at least 20%. Those old timers back then really knew what they were doing. Craftsmanship you can not buy these days!