I had no idea before that the signature on the damaged blade I bought could have any value other than historical (time of creation). A few weeks ago, I came across a post by Paul Martin and saw a beautiful sword signed by... Sa. It made me wonder, but who would get rid of a tanto from such a renowned swordsmith just like that?
The tanto has its document, however, it certainly won't be considered a high-quality sword. The seller pointed out that it has Hakabore.
I've already written to Mr. Martin, but not about the signature, only to ask for help in finding conservation rules. Maybe it's worth sending him some pictures, I'll see
Thank you for pointing out the mei, but I'm not getting my hopes up that my tanto was forged by MASAMUNE JUTETSU, although it would be good to have his blade even in this condition and with hakabore.