Ah, I thumbed thru a few makers & found the following in Dresden:
Karl Grndig - 1867
Hofbchsenmacher Sr. Majestt des Knigs Friedrich August von Sachsen.
Dresden, Gewandhautrae
Gebrder Kupfer, Bchsenmacher
Head of Guild
Frherer Inhaber: Engelbert Heinze
Gegrndet 1867
Walter Kupfer or his brother had a satellite office in Prag
Carl Friedrich Ulbricht - circa 1845
Gustav Richard Ulbricht Knigl. Hofbchsenmacher
Dresden - N., Kasernenstrae 23
Since it is only say 50 km to the CZ border and since Gebrder Kupfer had a satellite office in Prag, I still think the possibility exists that the family of Janeck did the same but in reverse? I looked for a Dresden successor to Janeck but for now have not seen one.
Cheers,
Raimey
rse