three folded lettersheets sent from New York City to Mexico, first franked with 10c Brown tied by February 17, 1877 duplex, addressed to Vera Cruz, purple "S.S. City of Havana" straightline; second franked with pair of 10c Brown tied by November 17, 1877 duplex, addressed to Vera Cruz, purple "City of Mexico" straightline; third franked with 5c Blue tied by October 21, 1880 duplex, addressed to Laguna, purple "Campeche" straightline, very fine trio of covers with private handstamps used by M. Echeverria & Co.