1926 50c. yellow & brown with bilingual "POSTAGE" overprint in violet used on cover from Ulan Bator to Moscow, tied by "ULANBATOR MONGOLIA/3.VII.26" double-ring d/s. Cover with a central vert. fold otherwise fine. (Tax Method: Regular Taxation) (Image)

1927 Red-band cover from Uliasutai to Harbin, China franked by 1926 25m. on the reverse, tied by rect. framed "ULIASUTAI/21-5-27" datestamp, also with Chinese 4c. tied Harbin '14.6.27' bilingual arrival cds, and Tientsin transit cds on front. (Tax Method: Margin System) (Image)

1928, 5m. greyish-lilac/black, five copies as correct 25m. rate on cover from "ULANBATOR 13.XII 28" to Kalgan/China (Zhangjiakou), charged upon arrival 20.12.28 by China 10c. blue, stamps and entire some postal wear/imperfections. (Tax Method: Margin System) (Image)

1931, 5m. on 5c. greyish-purple and 20m. on 20c. bistre, two values on cover from "ULANBATOR 25.XI 1931" to Kalgan/China (Zhangjiakou), charged upon arrival by Chinese postage dues 20c. blue and 30c. blue, slight postal wear as to be expected. Unusual. (Tax Method: Margin System) (Image)

1931 10m. on 10c. green IMPERFORATED and with SURCHARGE INVERTED along with perforated 20m. on 20c. block of four and two singles plus 1931 50c. optd. "Postage" on registered airmail cover from Ulan Bator to Harbin, China cancelled by "ULANBATOR MONGOLIA/29.X.31" cds, rect. framed Reg. cachet and airmail h/s both in violet alongside, and on the reverse franked by Chinese postage dues 10c. and 30c. strip of three at arrival and tied by bilingual Harbin cds, fine. A VERY RARE STAMP IMPERFORATED AND WITH INVERTED SURCHARGE and IN COMBINATION with perforated 'm?ng?' stamps and the 1931 50c. 'Postage'. (Tax Method: Regular Taxation) (Image)

1931 10m. on 10c. green with SURCHARGE INVERTED along with 5m. on 5c. and 20m. on 20c. block of four and two singles, all with interrupted perforation, plus two single of 1926 50m. on registered airmail cover from Ulan Bator to Harbin, China cancelled by "ULANBATOR MONGOLIA/15.XI.31" cds, rect. framed Reg. cachet and airmail h/s both in violet alongside, and on the reverse franked by Manchuria 1927 $1, 50c. and 10c. at arrival and tied by bilingual Harbin cds. Envelope with a small cut-out at bottom of front otherwise fine. (Tax Method: Regular Taxation) (Image)

1961, The rare souvenir sheets Nr. 1 to 6, all mint NH, undervalued in new Michel with 480,- (M) (Tax Method: Margin System) (Image)

1961, The rare souvenir sheets Nr. 1 and 2 mint NH, undervalued in new Michel with 160,- (Tax Method: Margin System) (Image)

1961, The rare souvenir sheet No. 3 "40 Y. Revolution" mint NH, undervalued in new Michel 160,- (Tax Method: Margin System) (Image)

1961, The rare souvenir sheets Nr. 4, 5 and 6 "Stock Farming" mint NH, undervalued in new Michel with 240,- (Tax Method: Margin System) (Image)