Nice Scabbard, BluErf.
I think you are very lucky to got keris like yours, because for now, it is too rare dapur.
The Paul's Keris is Malay. The top of blade similiar like a Malay or Sumatran keris. Nice Naga Siluman for collected.
About the 'C' underneath the naga's head, it could be a broken beard of Naga, so that it be came a "C"
. Perhaps it was "O", or indeed like "C"
I posted some photos of broken beard of Naga for comparison about the "C" at underneath the Naga's and photos of intact beard
So, the "C" is unique characteristic of your kerises
.
Regards,
Mans.