Postby silverfan » Thu Jan 15, 2015 6:48 am
The mark KW stands for Wilhelm Knewitz. In my source is written J. Knewitz what means Juwelier Knewitz. The present owner of Knewitz, Mainz (5th generation) Rainer Knewitz told me, that there was also a jeweller Jakob Knewitz (first generation), the father of Wilhelm Knewitz and that produced or bought items were marked with J. Knewitz. So I think it depends on the production time if 'J' means Jakob or Juweller.
Regards silverfan