These swords have been vetted as authentic.

NGOMBE prestige blades, called Ngala, are often called Ngombe Doko (Doko is a separate tribe that also used this blade).

They are often mislabeled as "executioner's swords", displayed ceremoniously to indicate the power of life and death held by the king. Highly prized, some could have been recognized and used as currency for barter, transactions and storage of wealth.

Thanks to Ethan Rider and Dan Mato for their expertise and help in correcting my attributions.