Stamps of Tannu Tuva

Tannu Tuva is a province in central Asia vetween Russia and Mongolia. In an agreement between these two countries in 1921 it was declared the Republic of Tannu Tuba, though few other countries recognised it.
It is perhaps best known for three things. Fistly the monument that supposedly marks the exact centre of Asia.
The there are the Tuvan stamps. While generally portaying Tuvan life, rhey do take some pictorial liberties. They are famous for triangle, diamond and parallelohram shaped stamps issued 1934-1936. They are not highly regarded amongst philatelists as they were designed, printed and sold in Mosscow, primarily for profit. A few truly used covers do exist though.
Richard Feynman the Nobel winning physicst had nay interests. His autobiogs are a hoot. He collected stamps and tohether with colleague Ralph Leighton was intigued by a country where both reindeer and camels roamed, and the unusually shaped stamps. They decided to visit Tuva. Bot easy for an American who worked on the Mangatten Project. Feynman practised throate singing and Mongolian noseflutes in order to compete in contests there. No luck. Leighton's book 'Tuva or Bust' details their efforts. Feynman died befoe achieving his aim, but Leighton did shortly after.