1924, Airmail 20 marka, tied by cds. "TALLINN 24 IV 33" to cover to New York, as airmail stamps were only valid for airmail fees. The cover was handled as unfranked and charged with a 50 c. surcharge fee; at arrival, franked with USA postage due 10 c., fine and scarce, certificate Löbbering BPP (2015)
