[David]

I personally stay away from polishing pastes, or anything that applies abrasion to the metal. I would any one of a variety of two-sided polishing/buffing cloths that jewelers use.
I have a few questions about this kris that you probably haven't figured out fully yet, but here goes.
The fittings on the sheath don't look silver to me. Can you determine what metal this is? Is it aluminum or some other kind of "white" metal?
I would like to find out if the silver bands on the hilt are actually silver or just washed or plated or maybe some other kind of silver metal. Cleaning them up might help in identifying them.
Are you sure the pommel is ivory and not bone? What happened to the underneath area that looks all chewed up? Some better, closer photos with more a angles of view would be helpful.
I think Ian and José may have more experience with Moro weapons than i, but my general feeling is that the dress at least is post WWII, not as old as they suggest. I also hesitate to place this as Datu class (implying that it was actually owned by a datu). I see a lot of keris in the marketplace that i would consider datu STYLE, but that seem to have been dressed to appear that way for the marketplace. I am not convinced that a keris that would substitute various white metals for silver is actually a keris that a legitimate datu would carry, though i could be wrong.