VIETNAM (NORTH) - Czechoslovakia. 1957 cover, bearing 50d Dien-Bien-Phu, 500d Railway issue, 5d Dang Ninh and 100d Russian revolution anniversary. All tied by Ha-Noi c.d.s. Rare commercial usage of 500d railway issue stamp. Mi. Michel 12A,34,42,64. (Photo). Est. 200 - 300 CHF.