Apologies for resurrecting such an old thread, but the keris I bought recently, show in this thread...
http://www.vikingsword.com/vb/showthread.php?t=19929
...also has what would be considered a "reversed" grip, and the blade is firmly attached to the hilt. I tried to pull it out or twist it as hard as I could and it wouldn't budge. It might have been affixed with damar, or maybe some western owner glued it into place. I'll try heating it up and see if it budges.