Kevin, your piece is a coconut husker, here are three from my (urban archaeology) stool collection F I Y (I have also posted a comment on your blog):
I have a few more but they are more 'tourist' pieces, the one above, from the Pacific region is very substantial . By that I mean heavy and durable - without the serrated blade but featuring a penis and balls, carved and positioned right where the female sexual organ (happens to be) when the woman is (sitting astride) and using the stool. The aged patina on this stool is delightful. It came from an important collection prior to being broken up in the late 1990s owned by Dr Peter Hallinan of the Gold Coast, Queensland, Australia.
The piece above is more South East Asian, much more finely carved and probably has Dyak origns. It came from a dealer who imported ethnic and tribal artifacts into Australia in the mid 1970s, again without the serrated blade.
This stool is again very robust, heavy and is a bird form from the Phillipines via another Brisbane dealer, Willy Conner who has spent numerous forays into the region for the past 30 years. I've managed to score these because the dealers are friends and know that I seriously collect them. To have a scraper intact is rare as natives usually only discard items that will no longer serve them or have lost their magic.
Here is a link to my stool collection on our other blog - enjoy!