I'm glad my thread-resurrection has stimulated some good discussion on the use of siraui...  
 
I wonder though, why are there such fine examples, and some of them dressed like keris, if it was simply a utility knife? 
The possibility of two forms, the often fullered ones and the ones with a choil(?) due to the edge dropping a lil from the tang... is intriguing. Maybe the siraui form was taken in a martial direction from the utility origins... ? 
 
Someday I'd love to own a few, if only for a little bit... Sumatran weapons just don't cease on seizing my attention.