I am so loving it as I make my way through your very rich website. Kudos on your social courage and observational acumen. And, please permit me to begin a sincere dialog by asking a big picture question.
To wit, the aggressive Spaniards plundered vast amounts of gold in vanquishing the Inca. But they never identified the source of that precious metal.
For example, a huge, solid gold disk was the central feature in the Inca Temple of the Sun (Cusco). It was recorded to be startlingly wide in diameter and as thick as a man's hand. But the Inca never expanded beyond western South America. And no ancient gold mines have ever been found there.
On the other hand, Egyptian mummies have been found to contain traces of both tobacco and coca. These are both New World products.
Do you reckon that the old gold mines in southern Africa could have been the source of the vast amounts of Inca gold? And that there may have been large-scale intercontinental exchange of valuable goods in prehistory?
If so, what maritime culture might have played the key transport role?