I recently purchased a 686-3 6" from a friend's estate. It had a scope mounted and the rear sight assembly is MIA. Ordered one from Numrich and it was the wrong one (front screw hole of sight tang doesn't match up with the frame hole). By my caliper measurements, it is 1.925" from the square machined surface on the back of the top strap to the center of the screw hole for the sight tang's screw.
Can anybody help me with an assembly for this?