Two West(?) Javaneses Keris with Sumatra style hilt

[Athanase]

Hello,

I recently acquired these two Keris which intrigue me a lot because their grip is very close to that of the Keris hilt from South Sumatra.
However, the base of these handles is typically Javanese.

The two Keris come from two different collections.
In both cases there is unfortunately no Mendak.
What type of Mendak would be the most suitable?