That sheath is definitely 100% Pattani so it looks like you have gotten yourself a composite piece with a (likely) Madura blade and hilt.
This thread though raises the very relevant connection between the North Coast of Java and the origins of the keris in the Northeast Peninsula. There is definitely a strong connection - all you have to do is scan through Karsten Jensen's book. The familial relationship is sometimes striking!
Now Detlef, all you gotta do is keep your eyes peeled for an early Pattani blade and a bangsa agung or earlier style coteng hilt.
