The company was founded in 1880 by Paul Aegidius Klesczcewski near Metz, Lorraine, from 1870 to 1918 Germany. In 1900 K. made or had made a see-through shotgun cartridge, the case made of celluloid. In 1906 they moved to Berlin W8, Friedrichstr.73. After Paul's death the company was owned by his widow Angela Kleszewski (spellig changed sometime to German habits) and run by his son(?)Witold K. Afaik the company existed until about 1973 as a sport- and photographic shop. Though they called themselves an arms factory, with photography as a sideline, "Waffen und Photo", I suspect they were retailers with some wholesale activities at best.
During the interwar years fancy stock wood and better finish were Steyr factory extra cost options.