British Cameroon. 1941. Official envelope headed 'On His Majesty's Service' addressed to Victoria, British Cameroons bearing French Camerouns Yvert 229, 2f50 lilac tied by Douala/ cameroun date stamp '3th Jan 41' with framed 'British Naval Control (Service des Routes Britannique/Duala/ French Cameroons' on reverse routed via Nigeria with boxed Passed by Censor/ Nigeria/ 19' censor in carmine with Victoria-Cameroons/ Under British Mandate' receiver '7th Feb' . Scarce item from the British Navy Control, Douala. Ex Maddocks and illustrated in his book.