cover 1926-27 covers (4) including 1926 (Aug.) from Ulan Bator to Moscow bearing "POSTAGE" overprint in purple 5c. and 20c., 1927 (Jan.) "red band" cover from Ulan Bator to China bearing "POSTAGE" overprint in black 5c., 1926 New Currency 20c. and Junk 3c. (3), 1927 "Stabinsky" cover to U.S.A. bearing various "POSTAGE" overprints (5) in purple.