France 1876 1fr bronze Type Sage Cover Paris to Guadalajara Mexico Paquebot

Folded letter, with contents, franked with 1fr bronze Type Sage (Type I), tied by Paris / Gare de l'Ouest c.d.s. (19 Dec), to Guadalajara, Mexico, endorsed "per St. Nazaire", struck "25c" in black, with Ligne B / Paq Fr No 4 ship mail c.d.s. transit backstamp (21 Dec), light horizontal filing fold well clear of adhesive, a lovely solo usage of the 1fr Peace & Commerce, signed Calves. (Yvert 72)