I was reading, well reading....looking pictures in a book about Lombok Keris. It is in the Indonesian language, so that's why I was looking pictures .
There was a drawing of a keris that had the same dapur as this one. Unfortenately no description about the prabot because the chapter was about pamor. It is not an uncommon prabot and can be found in literature. A shame they didn't use a line to name the dapur.
I found also pictures about the same style of dress. Carefully I would say that this keris is from Lombok.
Anyway, it is a beauty!!! Thanks for sharing.