Ethiopia maybe, but likely not South Soudan as they didn't make broadswords.
Your and Werecow's swords are virtually identical and could have been made in the same smithy. It would be interesting to compare dimensions.
The Ethiopian origin is only a guess. They had the sword making talent & skills and a my Kassala informant 1985 said they specialized in wide channeled fullers on broadswords. (Also, to my knowledge wide fullered blades were not typically included as 19 C. European trade blades.) Even though they preferred curved blades and bought finished single edged swords from England among others.
The blades could have been battlefield pick-ups from the Battle of Gallabat, March 1889, and redressed into Hadendawa kaskaras.
https://en.wikipedia.org/wiki/Battle_of_Gallabat
Best,
Ed