Some bayonets have been found in very very poor condition and totally modified to save what was left for the present owner. I find no resemblance of the OP's to any existing fighting knife , But only the one who made it can tell what it looked like when they received and thought about saving the blade to say a broken handle. Now I might be publicly castrated. But I was given a type 30 Japanese bayonet that had a blade so pitted you would cry. This had the quillion rotted away and the ring for the barrel was only partially there with no grips to speak of. Myself who likes to participate in weapons of time gone by, decided to make it into a Sai. Which I am quite proficient at and have practiced for over 2 decades. To me as a Bayonet collector I was not destroying something that would have turned into a pile of rust , But bring something back to life to serve its master and it has done well!
I had to remove DEEP pitting from 100% of all the metal seen. The grips I made out of iron wood.
I would like to also mention this was a Nagoya arsenal made Bayonet. One of the most common made. If it was one of the rare makers this undertaking would have never happen.
I did say "slightly", in this pic the blade reminds me a little of a Gerber MkII, it looks slightly narrower down by the hilt.
The shape of the grip is also vaguely reminiscent to the WWII USN diving knife.
It is really just a classic fighting knife shape, seen more or less replicated in many Western Allies fighting knives. The only thing really unusual is the pommel treatment.
Here's a Gerber MkII on a London Bridge web sheath, there's some similarities in blade design.