Bill, my feeling about this is that it is just lovely, but i can't figure our whether this piece serves a deeper spiritual function worthy of the name "spirit cage" or if it's just beautiful for beauty's sake. Either way is a justifiable reason for being.
Addendum: I don't get the feeling it is particularly old though. Which makes me wonder about the worn away kinatah look. That can be a popular dealer technique to make a newer keris look old. Or maybe it's just a way to save on gold coasts.
Either way it does make me wonder what a creation like this would look like in full stain and completely in kinatah as seems to be the original intention of the design.