I would agree with most of what you say Kai.

I do question the hilting (there is an awfully bright chip above one of the nails in the close up of the hilt); if the blade is substantial and thick at the gangya it probably is a combat blade.
We should remember that armed clashes with the Moro peoples continued into the 1930's so many blades made in the first third of the 20thC. were not really revival as much as they were actual weapons.
Yes, the workmanship seems to be of village quality; the 5 luk blade is a bit awkward in its execution; I would not be surprised at all if the brass dots and aluminium nails (possibly the handle itself) were not recent additions.
I am surprised by the lack of care in the forming of the greneng which leads me to suspect that maybe this is an eroded 19thC. blade that has been dolled up a bit.