Hey Shahrial, don't worry about it. Our 2 cents do not devalue; they contribute to better understanding.
I agree with the opinion that this piece is a parang nabur with an unusual blade form. I read in Zonneveld's book that not all parang nabur has the D-guard, but in this case, the D-guard and quillon was probably sawed off at some point in time. However, I thought it sort of improved the 'aesthetics' of the blade when it is unsheathed -- the hilt flowed more smoothly into the blade. I do recognize that it does look a bit funny in its sheath, with the wood on the scabbard mouth showing.
The straight blades in Zonneveld's book, and that in Dajak's collection actually has a bit of convexity to the cutting edge. This example of mine is completely straight. Could it be case of this blade being 'salvaged' from another sword-type? Does anyone recognize this blade form in other types of Kalimantan or Malay swords?
One last thing - anyone knows of skilled Kalimantan craftsmen who can do a good job with the D-guard and quillon?