Lengthy title on front; unusual photo of the British Avro with German markings. Postally used as Feldpost from Potsdam to Hamburg on Sept 22, 1916. Very collectable; very good condition.
Lengthy title on front; unusual photo of the British Avro with German markings. Postally used as Feldpost from Potsdam to Hamburg on Sept 22, 1916. Very collectable; very good condition.
