What excellent map and illustration of the complexity we are dealing here
Thank you for citing the 1676 citing of the axe, too! I can imagine now the possibility that the crescent-shaped head axe may not be Cordilleran afterall, but Ibanag! I hope we can get a collaborative source through diligent research.
Let me add to the absence of representation of the Ifugao on the "Ethnolinguistic ..." book
Ifugao:
Spear or "pahul" which can take the form of a "balabog", "kinango", "gayang", "ludit"; "hinolgat" (war spear)
Also uses the shield (2 types); ax (as a tool); bolo (2 types - "Pinahig" and "Hinalung"); bow and arrow (as an early weapon which became "extinct"); and lasso