I know this is an old thread but i want to share this with everyone I have a sword with a wobbly Tsuba Im guessing Parts were Not original
I tried adding more seppas but that didn’t work My wife mentioned go to Hobby lobby Smart lady Anyway i found foam rubber sheets that were sticky on one side They come in different colors I picked brown
I made a template using a pen seppa xacto knife and scissors I stuck the sticky side on one side of a seppa I needed 4 since it was really wobbly I made a thicker menuki and walla very little wobble Not pretty but it works
Steve