Hugues Courant from the Municipal and Metropolitan Archives in Brest France recently responded to my request for information on the maker of these pistols. Although they have no specific information on a Goyel or Goyet arms manufacturer, they have 3 registers of congregations of inhabitants and craftsmen for the period. These registers have been scanned and are available on their website. Unfortunately, there is no alphabetical index, and I don't speak or read French.
There is no entry for a Goyel or Goyet in Stockel or
Repertoire d arquebusiers et de fournisseurs franšais (The most complete existing reference of French armourers.)