1944 REGISTERED AIRMAIL TANGIER TO SAN JOSE, COSTA RICA WITH 5s RED (SG477) AND 10s ULTRAMARINE (SG478b) X 2. Envelope sent registered airmail from Tangier to San Jose, Costa Rica with KGVI 5s red (SG477) and vertical pair 10s ultramarine (SG478b) cancelled 'REGISTERED/BRITISH P.O. TANGIER' oval date stamps 20 JNE 44 in purple, stamps in part affixed by tape. On front 'TANGIER' registered label, at left Censor label and on reverse 'SAN JOSE' date stamp July 1944. Very unusual usage. (Ref 143049).