Small part of registered, 2-line "ΣΥΣΤΗΜΕΝΟΝ/ΑΡ.157", cover fr. with 20l. blue, 1871/76 issue + 30l. deep olive-brown and posted from "ΑΝΔ.ΚΑΣΤΡΟΝ (71)*21 ΜΑΡΤ. 77" with linear "PD" to Constantinople. (Hellas 41d+43b).