Welcome to the Warung Leif.
Bugis culture is spread throughout the Indonesian archipelago and we can see it's influences in blades from Sulawesi to the Peninsula. That said, i see more Javanese influence in this particular blade than Bugis (though it is not a Javanese blade). My first guess at origin might be Sumatra, but others who specialize in these types of keris might have a better idea. I would indeed agree that it is an antique blade.
I also wouldn't call this dress form Bugis per se. Personally i often miss the subtle differences that distinguish some Sulawesi dress forms from Sumatra and even the Peninsula, but i find it even harder with this relatively new dress as the features of the Jawa Demam hilt and the sheath seem to have been simplified even more over truly older dress forms leaving me little to go on. I can certainly tell you where it is not from (Jawa, Bali, Madura), but i will leave it to other to pigeonhole. I would only be guessing if said Sumatra on the hilt and sheath just like the blade. But i still wouldn't use the name "Bugis" to identify any of this regardless.
