The cancellation on your cover is a commemorative pictorial postmark used to mark a specific international diplomatic event. Here are the finer details:
⚓ The Cancellation Details
- Event Title: "2ª SESION DE PORTUARIA MARITIMOS-OEA" (2nd Maritime Port Session - OAS).
- The Sponsoring Body: The OEA (Organización de los Estados Americanos or Organization of American States). This session was part of the Second Inter-American Port and Harbor Conference.
- Location & Date: "MAR DEL PLATA (B.A.) ARGENTINA" | "27 MAYO 1963". The "(B.A.)" stands for Buenos Aires province.
- The Graphic: The central image in the postmark depicts a cargo ship at a pier with a crane, symbolizing the maritime and port development themes of the conference.
- Historical Significance: This specific conference is famous among international law and maritime historians for the adoption of the Convention of Mar del Plata (Inter-American Convention on Facilitation of International Waterborne Transportation). This treaty aimed to simplify and standardize the paperwork and procedures for ships moving between American nations.
🎨 The Envelope (Cover) Details
- The Cachet (Top Left): The logo featuring the seal is for PEFIMAR (Peña Filatélica Mar del Plata). This was a private stamp collecting club based in the city that produced "souvenir" covers for major local events.
- First Day of Issue: While the Sarmiento stamp itself was likely issued earlier, this envelope is considered a "First Day of Event" cover. In philately, the "Firts Day Cover" (misspelled on your envelope) text usually refers to the first day a specific special cancellation was used.
- Typography Error: Note the typo in the word "FIRTS" instead of "FIRST" on the left side. Such errors are quite common in locally produced private covers of this era and sometimes add a bit of "character" or "charm" for collectors, though they rarely increase the monetary value significantly.






