I agree with Kai Wee, the blade might not be a Maduran blade.
and also about the "gandik falling into the blade" feature is common amongst Sumatran Bugis blades, Sulawesi kerises, as well as Peninsular pieces.
I do agree that, trying to determine the blade origin, we'll have to ignore the dress, (for the time being) and concentrate on the blade's features.
The blade, might be of Sumatra/Kalimantan origin. Looking at the blade's features... the ganja iras, the ricikans, the greneng-works and the pamor. Probably an adaptation of different influences, made for a Bugis.
The blade, does have some resemblance to
Keris Kapak Cina.
In West Kalimantan, after the fall of the Majapahit kingdom, there were a few kingdoms which took shape. Examples are the Pontianak and Sambas Sultanate. Not much is known on the West Kalimantan hilt form. In Banjabaru and Banjarmasin, these places are already well-known for manufacturing exceptional hilt works. In general, it uses the same form as the Malays and vice-versa. However, hilts do get inter-changed within other communities in the Malay Archipelago. As we know, the bugis most commonly ply the Southern Borneo areas all the way to Sumatra and Malaysian Peninsular.
For the hilt type, I've seen it before (at Adni's shop) on a kris and a badek (kawali or Badi Guru), as well.
The hilt cup (pendongkok), does looks like a variation from a Palembang style, a variation from Kai Wee's example (in his gallery).
The sheath, a mix between a Sari-Bulan and a Tengah form. I've not seen this form before.
These are just my thoughts, I'm still confused about the overall ensemble, though...