Bulgaria: 1956 (24.10) Registered uprated 20st postal stationery envelope (Mi. type U20) to North Korea franked with 1L National Products and 20st Medicinal Flowers and 44st Plovdiv Int. Fair stamps tied by SOFIA date stamps. Reverse Pyongyang 1.11 and another native date stamp. Mi. 842,879,965 – SG 888,925,1000
