Hmmmmm ..... interesting piece.
So far, no one's really discussed the blade.
Perhaps I'll start it off, if I may, by saying that, as I recall, the damascene is comprised of metals which are not too dissimilar, thus giving an overall 'grey' impression.
The size of the blade is closer to Soenda and Bali kerises than Djawa kerises.
Also please note that the fret-work may not be of similar shape as that on later Djawa or Bali kerises.