Chris, Stahl means steel in German but there was at least one gunmaker was named Stahl. This is what I found by "googling" a gunsmith named stahl:

The rifle was apparently designed by Richard Stahl based on information
I found at http://www.archivingindustry.com/Gunsandgunmakers/directorylist.html

"Richard (or Reinhard) Stahl; Suhl in Thuringen, Germany. Two types of rifle designed by
this gunmaker may be encountered. The rarer, dating from 1869, embodied
a self cocking pivoting block action operated by a bulky two part lever in the
enlarged trigger guard ahead of the trigger. The 1873 pattern was operated by a
breech block extension lever running down the right side of the stock wrist. By
1880, Richard Stahl had turned to true Martini action rifles at the expense of
his own designs. He was succeeded by Babette Stahl"

Babette Stahl is believed to be the widow of Richard Stahl

"B. Stahl; Suhl in Thuringen. Listed in German trade directories of the 1890s
as a maker of ‘weapons and cartridge cases’ (Waffen- u. Patronenhulsenfabrik),
this business was run by Babette Stahl, the daughter (or, perhaps, widow) of
Richard Stahl, until sold in 1901 to G.C. Dornheim of Suhl."

I also found this info from a German auction house site:

"Born in Selb at court in 1832 gunsmith Reinhard Stahl was cartridge brass and arms manufacturer. He had 1858-1861 a small factory for Revolver in the US, returned to Germany in 1862 and worked in the gun factory Amberg. Until he settled in 1869 in Suhl, he constructed some revolver models. After his death his widow Babette led the factory until it's sale to Immanuel Meffert and George C. Dornheim 1901."