Japanese dagger in Aynu style?

[Tatyana Dianova]

Thank you for your insights Peter - it really explains the mystery!
I do not think that the eyes are rivets - they lay offset, and the angle doesn't match either. I do not want make any damage.
The small thing is a roll of paper with some signs on it. The roll is glued, I wasn't able to unroll it. It is included in a knotted half-sphere.