Thanks Jani for the once over analysis and translation. At first guess I didn't think it was that of the Kaisers, but the following link seems to suggest that the Kaiser obtained weapons from W. Foerster for gifts. I'll have to look but I don't recall seeing any of the Kaiser's weapons with a crossover stock.
http://www.nmm.ac.uk/collections/explore/object.cfm?ID=AAA2541 W. Foerster was a master gunsmith and a supplier to the Royal Court of Carl(1801-1883) von Preussen from 50 Tauben Strasse 50, Ecke Der Kanonier Strasse, or what I think to mean as also being at/near the corner of Cannon Street. Carl von Preussen was the 3rd son of King Friedrich William III of Prussian. Carl had 5 sisters one of them being Charlotte of Prussia, who had a very close relationship with Carl von Preussen demonstrated by her caring for Carl even after she was wed to Tsar Nicholas I of Russian. Carl von Preussen attended her coronation to the title of Tsarina Alexandra Feodorovna. Carl von Preussen visited Russian several times and this is the social network/connection that allowed W. Foerster to be a firearms merchant/supplier to kings and Tsars. Firearms merchants with a royal appointment or being interconnected to the court seems to really elevate the status of the maker/supplier in the eyes of many & the firearms merchant touts that thru advertising. W. Foerster seems to have had such a following in Russia. But W. Foerster hit the jackpot with his royal warrant/supplier to the Royal Court of Carl von Preussen as Carl took the military route for his ascension and by 1824 he had the rank of Major-General which was a stepping stone for head of artillery by the 1850s. Carl looks to have had a great interest in hunting and passed the passion by purchasing the Glienicke hunting lodge for his son Prince Friedrich Karl, which was yet another source for W. Foerster to supply.
Kind Regards,
Raimey
rse