IRC (cancelled 11/JUN/1973) with an original value of "1 PESO" surcharged in red "VALOR m$n 12" IN THICK LETTERS, also with additional postage of 20P. San Martin + 68c. Stylized airplane (to make a total of 1 Peso ley 18.188), very interesting piece with mixed postage and change of value and currency! (Image)