I came across these on my last visit to the AMNH in New York (lousy photos taken with my cell phone in low light and through reflective glass). They are all labeled as "halberd head with naga and blades," and identified as being from Java, from the "Eastern Java Period, Singasari Kingdom, ca. second half of the 13th century." What struck me was how much the single-edged blades on these resemble the blade of a Thai meed chaithong (photo courtesy of PUFF):
PUFF noting in
this thread that the extension at the base of the meed chaithong blade might be an evolution of the ganga of a keris. Additional confirmation of the influence of islandic Southeast Asian culture on mainland culture, I think.