Neundorf Zierporzellan / Porzellanmanufaktur Neundorf
Hobackestra
ße 65, Gelsenkirchen, North Rhine-Westphalia, Germany (and other warehouses in Germany)
Importer and distributor of Asian (Chinese) imports
This company has operated from the 1980's. The steins, Bismarck and the Skull, were first sold in 2007.
Reference:
Porcelain Marks & More
Ink stamped mark, introduced circa 2004, on a replica Schierholz skull stein, first sold in 2007. 
Replica Schierholz model 15, Fürst Bismarck, second generation stein. 
Ink stamped mark introduced 2004, from a replica Schierholz, Fürst Bismarck first generation, replica stein first sold in 2007.
Ink stamped mark introduced 2008, from a replica Schierholz, Fürst Bismarck second generation replica stein, featured centre top. 