Registered cover fr. with 2x10l yellow-orange and 20l/25l light blue 1900 Surcharges stamp (with the surcharge "a cheval"), canc. "ΝΑΥΠΛΙΟΝ*17.ΑΠΡ.901" and boxed "ΣΥΣΤΗΜΕΝΟΝ", arr. "ΑΘΗΝΑΙ-4*19.ΑΠΡ.901". 40 lepta for a registered letter up to 15gr. A very fine mixed franking cover. (Hellas 124a+133).