A Beautiful Moro Kris!

[kai]

I'd be tempted to limit the origin of this kris to post-Span/Am war to turn of the 19th century. What are the dimensions, especially blade length and total length?

Interesting blade with an unusually narrow streak of mild steel added to the higher-carbon steel in the middle of the sandwich construction. I agree with Detlef that some more polishing by hand and repeated etching would be worth a try: It's possible that neither of the steels will exhibit laminations of noticeable contrast; however, a finer polish may bring out some additional details including differential hardening, etc. as well as probably a more crisp border between the steels.

Regarding treating wood, you'll have to be careful in a tropical climate: If your kris have to adapt to a (continuously) air-conditioned environment, it would certainly be good to do this slowly (and probably avoiding fluctuations by storage/display in some sort of cabinet); in this case repeated treatment with raw linseed oil, possibly a final treatment with boiled linseed/tung oil, and an optional topping with microcrystalline wax would probably be a good idea. If you can't control the environment that closely, natural oils can lead to grow of mould! In this case it may be preferable to repeatedly utilize thin paraffin oil (with a final layer of microcrystalline wax) or no treatment at all and risking some more cracks (stable and controlled storage conditions would be important for long-term preservation and to minimize damage).

Regards,
Kai