Bidspirit auction | Portugal 1943 Caravel, envelope with

Portugal 1943 Caravel, envelope with a pair of MF625 1$75 stamps, making up the 3$50 postage, circulated by airmail from Lisbon to Madrid, Spain, re-sent to Barcelona and returned to sender. Censored in Spain with various marks and a CENSURA GUBERNATIVA band, an interesting piece.