Need help to identify an unknown Philippine bolo

[Sajen]

I have recently acquired this heavy bolo, I think it's Philippine but not 100% sure about it. I can't really say how old it could be but I think rough estimated first half of the 20th century. The blade form remember strong to the Negrito Dipalatas, as well the small guard from horn which you can see at the Dipalatas but the handle from horn is very different, the only similar handle I've seen by a bolo is this from Michael Marlows (VVV) bolo he has posted once: http://www.vikingsword.com/vb/showth...ht=Philippines.
So what is it and from where exact it coming? An other form of a Dipalata from Negritos from an other Philippine island? Something complete different?
Every suggestion and comment will be very welcome!
It's 61 cm long overall with a blade from 43,5 cm which is 7 mm thick near the handle.