Outstanding Tim! Thank you for sharing that. It seems we have brought the use of copper on these swords up a number of times over the years, and this is very well placed information.
I recall having a kaskara with a brass crossguard, and wondered why this was used rather than the more commonly seen iron guards. I was told at one point that the brass (or presumably copper) meant 'life' while iron was associated with 'death', and while simplistic, it seems to correspond in some degree with this concept.
Perhaps that kaskara may have been furbished by a Hausa smith to the west where these concepts were more in place? It should be noted that the blade also had the dukari (twin crescent moons) which also suggest Saharan provenance to the west of the Anglo Egyptian Sudan.
All the best,
Jim
PS What book is this from...looks like one I'd like to read!!!