Good day to all! I have a leather tsuba with an accessory plate I believe to be an o-seppa. I also believe the cross-shaped pattern to be gold. Looking closely at the edge of the tsuba, I am not able to discern any layers of leather; it seems to one-piece. Please see the two pics below. I have found some rather confusing facts about these nerikawa tsuba, being really ancient (Heian period 794-1185) but also being made right up to the late Edo/Meiji periods. Simply put, the katana took over from