WW2 Naval dirk: fibrous material identification?

[Rawa]

Maybe pics like this are of some use for You?

https://ebay.us/m/PhyHll

 

Edited May 11 by Rawa

[Conserved123]

Thank you all for your responses. Because of the historical sensitivity of this tanto, our training as cultural conservators prohibits us from disassembling, so I guess we shall never know what exactly is inside the tsuka. 

I do have a question though. It looks badly damaged, there are dents and chips everywhere on the metallic surface. Possibly has actually seen active combat? There are brownish-green substance between the arches of the seppa, looks like mud/dirt, some kind of organic residue. I was misinformed, apparently this did not belong to a family friend, it was donated to my university's teaching library, and prior to that, it is completely unknown. No clear provenance. Given that this type of tanto is so 'common', it feels like it is a testament of some kind of Japanese's defeat that resulted in these items becoming 'spoils of war'? 

I am absolutely haunted by the sadness and historical weight behind this tanto. What would be a culturally appropriate way to store it and care for it, does anyone know? The original naval officer cannot be identified, was likely killed in action, so what can I do to advocate for respect and care for this item that potentially has a violent past? 

Yes it is likely paper underneath samegawa, I agree. Thank you for being generous with your knowledge. 

Best
Luke