My brother found it in a box in his storage. It goes back years to a pack and move. It probably belonged to my father, who wasn't a professional chef, but he was a very knowledgeable hobbyist who knew a few professional chefs. I was told, growing up that he took classes from James Beard at one time. It almost looks like a broken steak knife, but the top of the blade is smooth and tapered. This is the original shape.
It's possibly a fish scaler.
A google search for PAL RH22 turned up just one result, with a picture of the same knife [plus sheath] & only one answer as to what it is.