Looking for historical traces of Ateliers de la Societé de Couillet

Dear Friends,
my name is Gennaro Reppucci, from Naples, Italy, and I am a railfan.
I apologize for my low knowledge of the French language.
First af all I wish to thank you for my admission to your WebSite and to your Forum.
I would submit you my questions because I do hope you can help me.
I'm looking for information (written documents and images) related to Ateliers de la Societé de Couillet and, more specifically, on 4 steam locomotives (3 axles, 2 coupled) that were used by the "Society for the Neapolitan Railways" (SFN=Società per le Ferrovie Napoletane) by 1889, and 2 more steam locomotives (3 axles, 3 coupled) used by the same company since 1892.
It will be extremely helpful to have information on both the Manufacturer (Ateliers de la Societé de Couillet) and the steam locomotives.
Thank you very much in advance for you kind support.
Best regards
Gennaro Reppucci