I require some Nikon optics archaeology in regard to the engraving of N.S. on the "Made in Japan" ring of a Nikkor 50mm f1.8 AIS lens. The style(font and white paint) are Nikon type. Is this recognizable to you? Personally I have never seen this marking. The engraving is professionally done. Would a previous owner gone through the trouble and expense to put their initials on a rather common standard lens? Or is this something that Nikon did? Why? What does it mean? I know that Nakamura Souichi was the designer of this lens series.
Has anyone seen other examples of this N.S. mark?