Merci encore FAB. Je peux traduire l'article maintenant.
With FAB's help we gradually connect the dots and fill in the blanks. Translation of FAB's post:
For a better viewing, I changed my photo hosting site. The last photo is the header off a letter from barrel maker Breuil-Aulangnier during the time of Claude Breuil.
Some information on Antoine Couillard: (See the information on the OP's gun):
Old family of stéphanois barrel makers, from at least the end of the 17th century with Claude Couillard born around 1686. André Couillard was born in Saint-Etienne on 01 August 1846 from Jean-Baptist, the founder. He was a barrel borer. He married Christine Landy at Saint-Etienne on 25 April 1874. In 1940 Magand succeeded Cuillard as barrel borer at 18 rue du Haut Verney.