Helleri
Sorry for late reply, I missed your post. I've taken a couple of pictures, one with flash and one without. Not sure if they will be much help. A member of another forum queried if the wood could be lignum vitae. This is a South American wood so I'm not sure if it could be. However I did do an experiment which showed that my wooden knobkerrie
did not float 
. So I have some more questions:
1. Is it made of Lignum vitae?
2. Are there similar African hardwoods that do not float?
3. Did Zulus have access to South American wood supplies?
4. Would anybody try to fake a fairly common African item using an uncommon and expensive exotic wood from South America?
5. Its not an African knobkerrie but a rare Inca ceremonial club?
6. It's not made of wood but cleverly painted metal/thermoplastic?