A Knife I Received From A Friend. His Grandparents Had Owned It. Seems Pretty Old And Rustic! Any Ideas?

I think it's specific to the early 20th century. Moroccan Koummya dagger. They look very similar, look kind of the same materials and the shape, and the bevels on the blade look identical.
#10 The expandable opening for a missing fabric purse.
It apparantly was valid till the 1st of April 1922.
That sort of Money was issued in lots of communities during the times of Hyperinflation in Germany till 1924-ish.