Have noticed rubber seppa fitted to some nihonto offered on e-bay lately , also seems the odd private seller has also used these items.
Always a bit of dodge going on with multiple metal seppa but this a new one.
Would I be right in assuming this a trick to tighten up loose fittings rather than something that was original.
Not sure how long rubber has been around but it is a stretch of the imagination to think that this was used by the period craftsman.
Any thoughts please .