Hi Rosanna,
I wrote an email to the museum yesterday asking if they could assist you in finding information about synthetic resin beads (manufacturing sites and export to North and West Africa) or have information about German-language publications on the subject. The museum responded quickly but briefly that unfortunately they could not give any helpul inormations... With a "maybe" they mentioned the "Africa Department" of the "Linden Museum Stuttgart", but after looking at their website I wouldn´t be optimistic.
BTW...: the Yiddish word is "schmOck", for exampel "...Trump is a schmock..." :-)
Sorry, late as always...