Hi Chris
Nice old sword. I find Congolese weapons to be very interesting and I believe your sword to be a Kuba weapon. After searching through my books and looking through various websites I believe that I have found a Kuba sword similar to yours. Please take a look at
www.memoire-africaine.com look under arms and then the section on Glaives and you will find a photo of a similar weapon attributed to the Kuba that is dated to 1900.
Miguel