Thank you Alan.
Hello Peter,
two other observations. First, by your later and much better pictures you can see that the blade isn't original to this scabbard. The "mouth" was made smaller with help from some sort of filler.
Second, the mendak isn't a Yogya one.
I really doubt that a keris like this coming from an abdi dalam. He will fit his keris with an adequate mendak and when the scabbard of his keris is broken he will let made a new one for the blade and don't let refit an old one.
Like Alan I know that purveyors in Indonesia are very imaginative by creating storys when they want to sell something (and not only in Indonesia).
Sorry to speak open words to you and I hope you haven't pay to much for this keris. You have a nice and somewhat rare sheath form, a very nice mendak and so far I can see a nice hilt. The weakest part of this ensemble is indeed the blade.
Don't worry, we all have learned the hard way.
Best regards,
Detlef