Agree, Congo tribal sword. Not properly a sickle as it is double-edged,, more like the gurade or shotel, as you mentioned.
The copper or brass strip winding on the grip seems to be indicative of the area.
Here's a Boa sword from the Azande tribe in Congo. The two halves longitudinally are slightly overlapped and forge welded to form a central thickening that stiffens the fairly thin blade rather than being fullered. I also have a Boa sword, like this one, but the grip is not wrapped.
See also:
Mambele Sickle sword which is a single edged sword, sharp on the inside of the curve. It also has a link to a YouTube video on how they are used. (The link shows my sword)
Another by a well known sword person :
African Sickle sword by Skallagrim. it also shows a map of the area that they are common in, central Africa, bordering the Congo to the north. He actually does some cutting with it.