Hi Rod when I say modern in reference to the Zande type throwing throwing knife I do not me recent. In my opinion I would not think it pre 1950.
As far as I know the Shi type of sword may have a large footprint. South East Congo certainly I have a suspicion the form travels further possibly to parts of Ruanda, Tanzania and even Northern Zambia, just my opinion. I am still after one like yours. I think it is a regional style rather than a style suggestive of greater age. I have this one.