The North German Confederation was set up on 1st Jan 1868. Its postal servies replaced those of Bremen, Brunswick, Hamburg, Lubeck, Mecklenburg-Schwerin, Mecklenburg Strelitz,Oldenburg,Prussia and Saxony.
Loads on Wikipedia https://en.wikipedia.org/wiki/North_German_Confederation
It's impossible to make a definite confirmation of a stamp being counterfeit by looking at a small image of a faded stamp. If you have doubts, and want to be sure, you'll have to get it expertized.
