Hello Kai,
thank you very much for your comment. I agree that this dagger belong definitely to the sewar family and I have seen as well some sewar without this feeble fullers most examples show. Great suggestion that the hilt is of the hulu lungkee rusa type which point out as well the northern Sumatra origin.
The scabbard show a great glossy patination which let me think that it could be from WWII area or slightly earlier.
Thank you again for this good comment!
Regards,
Detlef