According to the book, this kris is deemed to have very strong magical powers and to select its owner, and it is only said to have been made in Blambangan by Empu Supo, not to be attributed to tangguh Blambangan.
I attach the picture of another kris with dapur Pasopati and having some similar features (and differences of course), it was made somewhere and some time ago by Empu Tartempion (well-known to French collectors only
) and it selected me as its new owner