Very unusual old keris , any ideas ?

[Battara]

This is definitely a Moro, possibly Sulu, hilt.

Lots of trade between the Indonesian and Philippine archipelagos. I have seen Indonesian kerises owned by Moro datus.

There are many Moro kris hilts and krises that were made for children of datus. Perhaps this hilt is one of them onto a traded keris as a gift.