Welcome to the forum Rand.
I am not sure that this buckle has any direct relationship to keris other than it being worn as a part of formal dress. Is there some reason you believe there is a connection.
Belts that are used to hold keris in Jawa often have highly decorated buckles, but this seems to come from some other region. The Jawanese buckles look very different. Can't say i have seen any pictures of buckles like these used in connection with keris. Perhaps someone else has seen it.
