Because the MWNN conversion uses the '72 OT frame, the hammer nose is too low to have a rear sight notch. The first batch of guns from Italy had no rear sight whatsoever (just like the movie gun, which also used an OT frame). People who have that one say it shoots great without the rear sight because you are sighting down the flat top of the barrel. Then the rear barrel-mounted sight was added, which you can see pretty well in that video. It does offer an excellent sight picture, better than the '72 OT, as it is nice and square. But to some it upsets the lines of the pistol, plus the edges of the sight are somewhat sharp and it might be hard on your leather. I imagine the sight could be smoothed up some. If I had one I would probably try to find (or make) a dovetail blank that followed the lines of the barrel and do away with the sight. It would then sight essentially the same as my '51 R-M's, as I sight with the hammer nose even with the top of the barrel which places the front sight up in the clear and is a fast and clear sight picture. I just aim a bit low on the targets.