Airmail cover with typed return address on reverse 'Rem. Lotty Hersperger, c/o 122 Obera (Misiones), Rep Argentina' franked on front with seven copies of 1945 10c maroon and 1945 5c carmine (SG 753 & 773) tied by multiple strikes of OBERA Mi cds dated 13 ABR 1950. Addressed to SWITZERLAND. Obera, originally named Svea was a Swedish colony founded in 1913.