Perhaps it is unheard of, digging up an old old thread such as this...
But I'm also pretty curious about the method of use, and I don't think it's been answered.
But maybe the answer is looking at the ergonomics of the handle. There's 6 major ways to grip a knife if you think about it. They go something like this:
- Forward grip, edge down
- Forward grip, edge up
- Reverse grip, edge out
- Reverse grip, edge in
- Pinch/palm/ricasso grip
- Pistol grip for punch knives
From the look of it, it would seem to be awkward fighting with a Siraui in forward grip, edge up or down.
Maybe it was used in reverse grip, or ice-pick grip. Either edge-out and relying on slicing to get the job done..... Or perhaps a ricasso grip for stabs and horizontal slashes?
Perhaps someone who owns a Siraui can take it in hand and play with different grips to come to a more conclusive conclusion. Or perhaps speak to Gurus of Minangkabu silat...