Oh yes, it's very common

(I have 2 other Keris with this type of handle, but Ladrang warangka type).
It's just the association with this type of Warangka that I didn't remember having seen before. In addition, if the handle and the warangka seems to be made of the same wood, it's the difference in quality of the carving that put me in doubt.
I love this keris, but I just wanted to submit to your opinions some details that surprised me.