Spanish Plug bayonet to Filipino Dagger?

[kino]

As the results of asking around, I was told that this once was a Spanish plug bayonet. With engravings on the blade, and what looks like the initials SA, and Kamagong wood scabbard, it was turned into a Filipino dagger.
The blade is rounded on one side and flat on the other. I wonder if the hilts missing pommel was somewhat like a round ball like the tip of the scabards brass fitting.

Has anyone seen this type of dagger/bayonet????