Bidspirit auction | One Man Collection of Tannu

One Man Collection of Tannu Tuva - Postal Stationery Envelopes - 1935, stationery envelope 20k blue, printed on white paper, size 163x128mm, rhomboid interior (type a), sent in 1937 from Kyzyl, tied by black letter ''b'' ''8.1.37'' date stamp (Ustinovsky No.3.2), addressed to Academician Vladimir A. Obruchev, Russian and Soviet geologist, Moscow ''19.1.37'' receiving markings, minor reversal soiling with no importance, VF and extremely rare, just a handful survived, Ustinovsky #K1, Est. $5,000-$6,000