I'm not an expert-- but I have a ko-katana that I believe is authentic, it's signed by Fujiwara Kiyonori, has some signs of age-- the papers for it look pretty good, etc. (I'm as sure as I can be, in other words.) It had a perfect mirror finish (except in areas of wear), and I waited several months before re-oiling it. I thought I did good research-- I got the most pure expensive talc I could find, some high-quality pure mineral oil, and I did my best. I instantly noticed that the shine lost some of its glow-- and when you look fairly closely you can see streaks left in the finish by the talc. After more research I realized this was a big mistake, and I feel pretty bad about it. I didn't realize it would've been smarter to just add a little oil-- I thought leaving the old oil was the bigger risk than not using some top-shelf uchiko powder.
Anyway-- it bothers me now. Maybe I'll get over it, or maybe I should just pass the sword along to someone who knows what they're doing. But-- I thought I'd ask if there was any sort of super-mild thing I could try to bring back that finish, and undo the damage of the talc. I realize that's a terrible thing to say if this is authentic-- but to get it re-polished in Japan would cost more than the value of the sword. If I were to try something extremely mild-- what would be the smartest choice?
Thanks for your time,
Lowell