Great Britain. (French Air Force in Great Britain). 1945. Royal Air Force envelope 'Per Ardva Ad Astra' addressed to France written from 'F.A.F. HQ, 15 Queensberry Way, London' bearing Great Britain SG 488, 2d pale orange and SG 489, 2 1/2d pale ultramarine tied by 'Postes Aux Armees B.C.M. 7' double ring '26th Jan 45', with blue-green Provisional censor label tied by oval 'Ouvert Par L'es Autout Controle' and circular '228' on reverse in blue. Scarce item from the Bureau Central Militaire in London (with letter).