cover 1927-29 native envelopes (6, four opened-out) from Ulan Bator to Peking and Kalgan (5) bearing various 25m. frankings (5) two mixed issue with Second Definitive values, and one 1t.; in combination with "Junk" 4c. (4) and 10c. (2) frankings, showing Chita, Manchouli and Harbin transit c.d.s., one with large "T" Due h.s.