envelope addressed to Ireland bearing the forces label "MALTA IS GRATEFUL/TO THE ROYAL NAVY/AND THE ROYAL AIR/FORCE FOR THE SAFE/ARRIVAL OF THIS LETTER." which has been cancelled in London by the machine "PAID" postmark in red, censor mark and signature" /> Air Mail cover 1941 (6 May)<I> "On Active Service"</I> envelope addressed to Ireland bearing the forces label "MALTA IS GRATEFUL/TO THE ROYAL NAVY/AND THE ROYAL AIR/FORCE FOR THE SAFE/ARRIVAL OF THIS LETTER." which has been cancelled in London by the machine "PAID" postmark in red, censor mark and signature | Christie's