Nechesh - thank you very much for your reply. Any help and any opinion is valuable for me, until any books about this weapons are out of my sight.
Here it is - THE PENDOK IS TAKEN OFF. And what do we see?
In my opinion the sheath is made of newest wood, so probably it is reconstructed. The warangka is damaged and probably this is the reason why someone took off the pendok and changed the sides - just to hide under the deity's head this bad looking crack. You won't probably see it on photos, but this crack is shining with glue leaking out from the other side. The warangka is glued to the rest of the sheath. I wouldn't be surpised if it was repaired crude European, but could European made such part of the sheath? - or do you think it's Indonesian work?
I was right - the pendok is made of gilted brass. The head is probably cast of brass. There you can also see the brownish stains on the other side of the head - which are probably the result of oxide.
About the stones - I must admit I'm confused - you're not the first person who doubt in "rock crystal theory". The expert was "quoted" not without the reason
- although she is still expert but not jeweler nor gemologist
. I'll look further.
On one of the photos you can see how badly is the head unriveted. There is a chance it will be repaired!
Best regards!