Anyone have any experience with the Jack Weigand rear sight for S&W? Need to replace the rear leaf on my 19-3 and like this option but I’m curious if you need the full screw replacement kit with spring or just the Windage screw and retain the spring? Also is the sight nut spanner tool essential or is there another option? I only plan to swap this sight once and my other revolvers all have rear channel sights. Any help would be appreciated.