Battara - So, if I understand correctly, Rick's spear on the left up in reply #2 would not be called a
budiak as it lacks the chiseled panel, and only the 4th from the left in the panoply shown in Maurice's post (#4) would qualify for the name
budiak.
In a playful vein, I shall, for the moment term this old Sulu spear as a protobudiak.
I have built a composite picture below - not to precise scale and digitally bleached to bring up more detail in the bases - in order of similarity of features. Our protobudiak is fullered and has no elaboration at its base; the blade tapers into a square cross section. (Maurice's splendid provenanced
Sulu spear would come next in this sequence.) The
second spear from the left below has a shallow chiseled panel which carries into a square neck as a line before an abrupt, but slight expansion into a round base. The
two on the right are proper
budiaks with a well developed chiseled panel and the thicker edges terminating in a classic floral? curve. These have rings around a round neck and re-expand substantially to meet the ferrule (or be partially covered by it in the right example).
Krieger's
plate 6 does strongly suggest both forms (chiseled with complex base and non-chiseled with square base) remained in use by both the Moro and Bagobo until the early 20th century. So chronology versus geography (of manufacture) or more likely a bit of both.