Entire letter fr. with 10l. red-orange with both digits inverted (pos.123/faults) + 2x40l. grey-mauve on blue with faults, posted from "ΚΩΝΣΤΑΝΤΙΝΟΥΠΟΛΙΣ (ΤΟΥΡΚΙΑ)*24 ΟΚΤ. 73" with oval "ΔΠ", via "ΠΕΙΡΑΙΕΥΣ (2)*28 ΟΚΤ. 73", arr. "ΑΘΗΝΑΙ (1)*28 ΟΚΤ. 73". Very rare on cover. (Hellas 26aNc+42IIb).