Thank you all for your replies
I have a number of these spears and spearheads and as mentioned, the Sudan, Zande or Mangbetu are likely sources.
The annoying thing for me is that putting 'Zulu' in a listing artificially increases the price.......it means that an African piece that is worth say £50 (or thereabouts) ends up to be £100 + because of the inaccurate zulu tag. The only 'winner' is the seller.....
Also, this type of spearhead would NEVER be used as a short stabbing spear, the barbs would never allow 'easy removal' from the victim. These are throwing spears, designed to be difficult to remove to cause the opposing warrior severe problems even if the damage is not fatal.
Yet this 'zulu' spear is only 29" long, you can see by the listing photos that it has been cut. (originally to make it easier to pack (if this was a conflict 'bring back') or more sinisterly, cut by the seller to give the impression that this is a stabbing spear)
Regards David