Block of Four 1928 native cover from Ulan Bator (7.6) to Peking (23.6) bearing 1924 5c. and 1926 New Currency 20m. in combination with China "JUNK" 1c. and 4c. pairs, 1931 (c.) registered native XU5 from Ulan Bator bearing 1931 (Oct.) fiscal surcharged "Postage" on interrupted perf. 5m. on 5c. and 20m. on 20c. in combination with China Postage Due 20c. and 30c. cancelled at Kalgan.