Thank you, Robert, that sounds totally credible. Those makers probably developed a lot of skill by doing this technique many times over.
I'm thinking that these so-called African knives are hard to identify because they were crafted in a rural tribal society where there were no smiths catering for the needs of the tribe. It was every man for himself: you needed a knife - you made it! Conversely, in old Nepal you had the kamis who made kukris for their customers. They used a forge of sorts and employed assistents for the more menial tasks. I'm thinking they made kukri-making more of an industry than the makers of this African knife. In Indonesia the empus made kerisses likewise. I think the African tribal maker/craftsman only had what nature provided and what metal was available to make a dagger or knife, and then mostly for himself and probably a small number of friends less talented than he. So what we have then, is a relatively large number of makers, each putting his own signature style on his work.
What I've written above is all conjecture on my part. I don't have a collection of African blades for scrutiny and comparison. I hope forum members will set me straight. (But if I'm correct, it means African knives are very hard to pinpoint culturally and geographically.
)
Johan