Visayan sword? Identification needed!

[Sentrad]

I bought this “rare Philippines sword” some time ago, but I have no idea where it is coming from.
It is a single-edge stabbing sword with a long thick shoulder and spear point. The shoulder is deeply impressed with alternate groups of three sickle marks and three arrow head form (?) marks. The blade has a crusty brown patina.
Very interesting is the handle, it is elaborately built up hilt with broad finger stalls and hook form terminal. The broad tang is flanked by an alternate horn and copper lamination, three each sided. The horn strips are inset with tightly spaced copper hobnails, most of them lacking. At the pommel where the tang ends are some more layers. At the outside of this construction are finely formed thick tortoiseshell scales. The whole grip-tang-construction is fixed with a row of 16 brass rivets. The grip bottom is deteriorated at both sides.
Total length 65,2 cm; blade length 49,9 cm / 19 1/2"; max. width 2,6 cm; max. thickness 0,7 cm.
For me it is absolutely impressive sword with a handle like a Naga.
Every comment would be very welcome.
Udo