Integral octagonal bolster/pilaster? Wow; cool sword! My interest in swords is as swords, not as Bornean (etc.) cultural artifacts, so the question as to age/origin of handle is of marginal interest to me, and even less do I have input on it. Cool sword though.
Very cool. More usually those I've seen are fairly lightweight. Both the thickness, especially away from the base, and the bolster seem to link it to non-Borneo Indonesian swords.