That's way cool stuff Wayne!
I read Peter Capstick's "Sands of Silence: On Safari in Namibia" while sitting in a blind waiting for a badger in South Africa recently and he covered these weapons and their use of them by the bushmen in Namibia in great detail.
I discovered much about the bushmen cultured during my first trip into Botswana 2 years ago, and I became quite intrigued by it. While there in Kanana I read much from a book on their history that Claire shared, witnessed the historical native dance put on by the local bushmen women, and had the pleasure of Happy's company every day as I observed his unmatched skill on the track of both the wounded and the not yet seen game animals there, not to mention the impressive eyesight that allowed his detection of animals that I eventually saw after minutes of almost disbelief while struggling even with binoculars to see what he did with the naked eye at great distances.
Sadly, the bushman's way of life that has served these special people for so very long is rapidly disappearing.