This construction 's not very famous. That 's why you gouy can't find it from documents published in the west.
According to an kris expert this piece might be "Sonkhla-Nakorn(SriDhamMaRaj)" (northern Malaya) design. The hilt is "streight beak Coteng". This construct mostly held by buddhist people in the class of artist or shaman medic.
Here 's a similar piece with the same construct...
Another piece...