Hi Royston, welcome .
Do you have a copy of Stone's Arms and Armor ?
There are two possible matches for your knife in this volume .
One identification could be a Buyo knife fig. 203, pg. 158 or it might be an example of a Tuba knife fig. 815, pg. 641 .
Of course it also could be neither .
I'm not sure if the apparent 'chisel grind' edge is common to the Morolands .
Both examples are listed as coming from the Southern Philippines as the style of the scabbard suggests .
Which edge is sharpened; concave or convex ?