Most interesting post, guys.
I've been reading and looking at the added links.
As promised, I post pictures of this keris (or Tappi as Sipakatuo pointed out) when in my hand. At first, I want to state that it's a small keris with a small handle and I have big European hands
Here is first, in my humble opinion, the best way to hold this keris. The handle, when sheathed, would point a bit to the front, away from the wearer's body.
Secondly, I put the handle in the position it was when I got this piece. I must say that, after straightening the peksi (or watting), it was easier to get a grip. Before there just wasn't enough room for my fingers. Therefore, I believe the peksi was bent by accident in the past.
I must say in this way you also get a good grip of the keris. This grip and the first one make it possible to deliver straightforward thrusts and also cuts.