TANNU TUVA - China Incoming Mail. 1933, 15k on 6k orange yellow, surcharge type 3 (5.1mm in hight), vertical strip of three used on back of registered cover from Kizil to Harbin - Manchuria, showing alongside Chinese Post Office bilingual arrival c.d.s., light filing fold away from the stamps, fine, signed Holcombe. Multiples of this issue are very rare, and commercial usage virtually unknown. This is the only reported commercial cover from Tuva to China. A gem of Chinese and Touvan philately. (Photo). Est. 3 000 - 4 000 CHF.