Auction # 2510 WORLDWIDE + ARGENTINA: Special March auction

UNUSUAL MIXED POSTAGE: Cover sent by OCA to a "PO box" address, by a regulation of the Official Post the private post (in this case OCA) was charged a single rate for the delivery to the PO box, which was paid with a 75c. Condor stamp. It also bears the mark: "PIEZA ENTREGADA POR OCA EN CASILLA DE CORREO DE DESTINO", VF quality, few known examples!