So recently got a Takahashi naganobu daito, and noticed this odd rust on the kissaki. Almost looks like a hagire but it's not present on the other side and isn't straight. Here are some pictures. Any thoughts on how this could've formed?
Bruce
I found that this gunto was made in the final month of the war 昭和弐拾年八月 (August 1945). The swordsmith was 長弘 Nagamitsu, 野呂山麓住 Noro-san roku jū( resident of the foothills of Mount Noro).It has convas cover.
It does look like someone did a superficial buffing wheel job on it, decided polishing wasn't worth it, and sold it as is. Doesn't mean they were right, mind, but it does look like trying to revive it might mean removing fatal amounts of metal. I have a blade here that had worse done to it - instead of the buffing wheel they went for the belt sander