Hello Andy,
Here's another recent thread of interest:
http://www.vikingsword.com/vb/showthread.php?t=13168
Bamboo (or rattan?) is not typically used AFAIK. I guess, this got restored before your father bought it. Since the pendok is covering it, there's probably little reason to change the current configuration. If you don't have high humidity, the wood will certainly benefit from a good wood oil.
The blade seems to be of lesser quality but I've been wrong before. I hope the specialists on keris Jawa will join in with suggestions...
Regards,
Kai