Rembrandt's Kris (?)

[ariel]

OK, now is the hard part :-)
Here is a famous Rembrandt's self -portait with a dagger. Usually it is described as a "Kris"
But... The width is strange, the tip presupposes the existence of a Turkish yelman, the gangya is peculiar and the luks are only on one side.
We cannot say that Rembrandt was a lousy or an inattentive painter. So, what kind of keris did he have, and was it a kris at all?

With a long weekend ahead, there is plenty of time to ponder the mystery:-)