Lot 30854 – 1929 Envelope sent by registered airmail from Ulan Bator to Harbin franked with 1926 issues paying correct airmail rate, China postage dues

1929 Envelope sent by registered airmail from Ulan Bator to Harbin franked with 1926 5m, 10m, 25m and 40m paying correct airmail rate (from April 1929 for registered cover abroad 25m postage + 25m registration + 30m airmail supplement), all tied by Ulan Bator cds and in addition straight line Russia AIR MAIL violet handstamp, alongside boxed Ulan Bator violet registration mark, reverse shows China block of five 10c Postage Due stamps cancelled by Harbin bilingual cds, small portion of envelope excised at lower right, a rare Mongolia airmail cover (Mi. 20-23).