Kohlenhofstraße 60, Nürnberg
An example of the work and mark of Felsenstein und Mainzer:

F&MN
Member Bahner wrote:
Felsenstein und Mainzer from Nuremberg, Germany. They never made any silver, just silverplated stuff like this one and fine German art nouveau pewter.
Simon Felsenstein (b. 18.12.1861 Fürth) and Sigmund Mainzer (b. 8.11.1863 Gaukönigshofen bei Ochsenfurt) established their business in 1886.
Users of the trade name 'Norica Zinn'
The business was acquired by Gebrüder Bing in 1918. The products of Felsenstein & Mainzer continued to be manufactured up to the 1930's.
Trev.