Most likely it's a Champion and the seller didn't open the fish scaler. A surprising number of sellers do not open tools that don't have nail nicks on them. Early in my collecting I bought more than one "Modeler" that was actually a Champion (new style) where they didn't open the saw or scaler. In fact, I've lost track of the number of knives I've bought where the saw or scaler was closed - one knife (my 84mm Hiker) I explicitly asked the seller - is there a saw? Look close, it doesn't have a nail nick but it opens from the end. "Nope, no saw". I bought it anyway because I was 90% there was one, and sure enough there it was.
This is especially common on old knives where the liners all go to the full height of the knife, unlike the recessed liners they use today. On these older knives it's pretty easy to lose the saw and scaler in the liners. There is a small chance this is a Master Craftsman LNF, but odds are it's a Champion from the late 1950s.