The third knife is probably the oldest one. On it, I found a little label with '19th century' written on it. The blade is real heavy. At first, it looked like a spear blade, converted into a dagger. But the blade has a tang, which is unusual for Central African spear blades.
I have no clue from which tribe this could be.
Total length is 33 cm with a blade measuring 24 cm (without tang). The wooden handle is entirely covered with copper binding.