David,
thank you for showing your UMETADA TSUBA for comparison. It is a nice one, and although burnt, it still has everything that makes a good reference TSUBA! As they were very likely not quenched and hardened, might it not be possible to restore it by just carefully removing the scale? Just a curious question.
As to my TSUBA, I have thankfully received helpful input to two of them, but the KO-TOSHO seems to remain a riddle not only to me. I am still behind it and looking for information. Could it be that part of the SUKASHI was added at a later date, thus obscuring the symbols meaning? What do yo think?