Rusznikarz/gunsmith J.(Jan?) Specht hung out his gunmaking shingle as J. SPECHT Fabryka broni i amunicyi in 1861 at Wielko Rycerska 6/7(Größe Ritterstraße 6/7) in Poznan till around 1872 when he moved down the street to Wielko Rycerska 8(Größe Ritterstraße 8) where he stayed until the mid 1880s. In the last decade of the 19th Century he was located at Rycerska 3(Ritterstraße 3) where his successor( nastepca wlaczone) J.K. Chmielewski acquired the business circa WWI. Just a guess, but it is highly possible that this was his son-in-law. At this juncture the shingle read J.SPECHT nastepca wlaczone J.K. Chmielewski till WWII at Franciszka Ratajczaka 3, which appears to be the same location but a name change was made post WWI.

J. Specht in Poznan
Courtesy of Piotr J. Bochynski - The advert seems to indicate a founding of 1864?
Kind Regards,
Raimey
rse