I'm sorry, I probably answered too quickly yesterday by launching the first intuitions that went through my head.
Yes I know they are two very different origins but if I said that it is that they are two cultures where I have already seen this overall shape of the blade, and which also have blades with very worked pamor (in particular the small loop at the base). Thinking about it in Sulawesi too we find very worked pamor of this type.
I also think the hilt was carved specifically for this blade and both are old.
If the hilt isn't Nias (Nias don't have pamor blade), it may be from Sulawesi where he also has hilts that look more like a dragon than a Makara.
http://www.vikingsword.com/vb/showthread.php?t=3953