CGA airmail cover franked with 1920 500rs blue 'Industry' definitive, 1929 500rs purple 'Santos Dumont' issue and 1927 2000rs on 10000rs black AIR overprint issue (SG 337, 451 & 472) all tied by PORTO ALEGRE R.G. DO SUL cds's dated 31.X.1930. The cover is censored with black on white 'ABIERTA PELA CENSURA NO RIO GRANDE DO SUL' censor strip due to the revolution of 24th October in which Washington Luis & Prestes were ousted and Getulio Vargas installed as the new president. Addressed to UK. A very rare censor from the period that ended the Old Republic.