Thank you all very much! Where can I find more information about the master and marks? I found the book here: https://books.google.bg/books?id=SsquCgz6WGQC&pg=PR1&lpg=PR1&dq=Goldschmiede+Niedersachsens:+Daten+-+Werke+%E2%80%93+Zeichen,by+Wolfgang+Scheffler&source=bl&ots=xVDkmH1y...