USSR stamp. M4 helicopter hovering over the Great Kremlin Palace. A 6 kopecks overprint on USSR stamp of 1960, 60 kopecks (denominated ten-fold). Unused. CPA No. ?.
USSR Ministry of Communications
Stamp - 1960/overprint - 1961
Original scanned by <a href="https://ru.wikipedia.org/wiki/User:Vizu" class="extiw" title="ru:User:Vizu">Vizu</a> from personal collection.