All the German mechanics with which I have spoken refer to the "no-name" sporting arms as trade guns; guns made by the trade for the gun trade. I think few concerns made every component inhouse, if any. It may be semantics, but there weren't any guilds that made guns for the trade or that took a master's example and peddled it. It's all folklore, hype and used as a marketing ploy for resale. Guilds took care of their own, providing for the widows and children of master gunsmiths. The guild was a guardian of the craft as well as a guardian of those within the craft. It was up to the individual craftsman for the sourcing & the marketing.
Kind Regards,
Raimey
rse