Just installed my sight. Not sure it fit quite right, but I got it installed none the less. I also noticed that when I tightened down the set screws, that the elevation arm was binding.
All I did to fix the problem was to loosen the screws, and then tighten them again. I think I got the torque a little more even this time and the arm doesn't bind any more. Maybe that is the reason that the stock sight only has one set screw? In any case, I was glad not to have to do any surgery.
