Hi Martin,
the three upper sickles I think are dancing sickles from the Dadiya (9°36'/11°30'), called "jen'nyi". Christophe Evers wrote in his book "Art of the Upper Benue River" that these ceremonial weapons used by young men in their coming of age festival "kal".
This other rituell throwing knife called "cicawa" comes from a small group called Ga'anda (9°30'/12°35'), like the Dadiya, a Chadic or Adamawa speaking ethnic group living in Nigeria at the upper Benue river.
This "cicawa" are never used as weapon, but are carried by the guardians of the initiants at the end of the boys initiation.
Hope it helps a little bit .
All the best in Nigeria
Wolf
www.spearcollector.com