I so want this to be right but I am having a few doubts about it being genuine as we would want.
As a trade blade it is far to roughly forged. Most trade knives and repurposed table knives are well made and quality steel. The table knives show signs of remodelling or changed by sharpening. The scabbard form does fit some Native American knife cases, search AMNH Database. The decoration seems odd but there are no rules on what the decoration should be. The way it is constructed is like many African and Asian knives, the forging looks rather African or somebodies idea of what a Native American knife should look like. There are a few painted geometric style scabbards on the AMNH Database. If you acquired this knife at little cost you might have been lucky. Take photos and send to museums and let us know what the response is. Good luck.
https://anthro.amnh.org/anthropology...0%20%2F%201149