Sorry: I tried to just add a comment to my prior post, but I couldn't figure out how to add more photos. This is in response to Saipan59

OK. I've taken a good look at the items you mentioned, and added some more photos.

The light scratches are on both the shinogi-ji and the ji. I can't really determine if they are continuous, or were done separately just meeting at the shinogi, which still seems pronounced and straight. The hamon is still quite visible, and in fact the "scratches" can barely be seen on the harder hamon.

This is only the second Japanese sword I have acquired. I bought it through an auction where it was presented as a: Japanese katana in shirasaya, shin-shinto (1765-1867), suguha hamon, ko-itame jimon, signed 'Suishinshi Masahide', original tang, iron tsuba with gilt inlay from Edo period; together with a silk katana bukuro (sword bag), total length: approx. 41", blade length: 28.25".
One of the reasons I bought this is because it appears "unfinished" and I wanted to add same,ito, mekugi, koiguchi, kojiri, etc.