Thanks Kathleen of http://katebomz.tumblr.com/ for pointing out this picture from http://www.flickr.com/photos/nationalarchives/5404812081/in/set-72157625849884949 with the following caption:

Miss Lucy Lameck, M.L.C. (left), Organising Secretary of the Women’s Section of the Tanganyika African National Union and Miss Victoria Kopney are seen wearing the proposed national dress for women designed by Miss Lameck.