IMHO as you read "Ki", not "Ke" Emil Kirsch of Berlin, gunsmith, mentioned about 1910, was the likely retailer of your gun.Sorry, but nothing more is known to me. Emil Kirsch is the only other "Emil K.." besides Emil Kerner, Suhl, Trübenbachstr. 3/5. Emil Kerner opened about 1889/90. By 1921 the company was known as "Emil Kerner & Sohn". 1928 Emil was no longer mentioned as one of the owners.