Schmid's 'Lexikon' just says that this company 'manufactured and sold hall clocks'.Doug Stevenson, in the 2009 Clock and Watch Bulletin -Gong Ho - confirms that Norddeutsche was the creator of this gong.
Mikrolisk indicates Norddeutsche was located in Berlin, which leads me to believe they were not clockmakers, but were makers / distributors of clock parts to the industry.
Perhaps Schmid's Lexikon can provide more information.
Regards.
JTD