Welcome to the forum, Spearcollector.
Lew is right when stating that this spear is a 'marriage'. the shaft looks much older than the blade. I haven't seen this type of spearblade, yet. I'm still young, though
But, Lew, the shaft is not Kuba. It's a typical shaft used by the Ngbandi, Bati and/or Benge living in northwestern Congo.
Here is a Ngbandi spear in my collection :
