In case this Trisula is not a later forgery, it could be quite a lot older then Michael's one (and has some substantial differences). It looks like an excavated object.
This might be a hint that the old Bupati mentioned is Raden Adipati Arya Kromodjoyo Adinegoro IV
https://id.wikipedia.org/wiki/RAA_Kromodjoyo_Adinegoro
If this would be an old and excavated object indeed, I doubt it would come from another regency, even more from outside of land of Java.