A while back a member here bought a OM gun that had the rear sight missing, He posted a WTB for the sight. I have a OM sight that I value at $75. I offered it FS and then member figured out the new one will work and ~$40. The gun was to be a shooter so he went with the NM/OM sight. The NM sight does have the little hole in front of the blade, OM does not have the hole. I also think that the NM sight lettering is just a tad off when compared to the OM sight, a little more scroll to it.