Fish Knife Pattern

The fish knife is a toothpick or tickler frame with a fish scaler, either on the spine of the single blade or as a second blade incorporating a notch at the tip as a hook disgorger. A bottle opener is sometimes built into an extended area of the tang on one of the blades.
Charles Gorrecht
I have a knife like this from my Norwegian, Grandfather.who was a Whaler. It is this pattern. It pre-WW2, blade is stamped ” Germany”. Handles are a mother of pearl or fake with a nickel badge.with the knife’s name: “Fish Knife”.
When did this pattern begin?