The first knife looks for all the world to me like an old trade knife, such as what we would consider a "scalper." My thoughts for that are the wear pattern on the blade from repeated sharpenings. The Natives preferred softer metal knives, as they would sharpen up with just regular rocks, but when the traders introduced better quality metals they balked, as the knives ate up their grindstones.
I don't have it in my hands, or I might could tell you a little more. I'm not even stating specifically that's what you have-merely that is immediately what came to mind when I saw it. Kinda felt like staring at a ghost.