Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Costa Rica - 1921 (April 10), cover from Experimental Unsuccessful Flight San Jose - Managua, franked by Mauro Fernandez 5c orange and semi-official air post stamp ''Costa Rica - Nicaragua'' of 1col green and yellow, minor cover folds, still F/VF, Sanabria #501, Est. $250-$300, Sc. #72