Sorry, can't answer your question, just have remembered to have seen this shields before and have looked where I've seen them and have given the two links. Also when when I am interested in African arms I don't collect them and I am far away to be an expert in African arms.
Maybe Martin or Wolf-Dieter will be able to give further informations.
Regards,
Detlef
PS: I am a little bit surprised that Colin don't respond until now to his own thread!
