Netherlands East Indies. (South Africa - Indonesia). 1950. Air Mail envelope addressed to Medan, Sumatra bearing South Africa SG 120, 1s brown and blue tied by Pretoria slogan '19th April 1950', endorsed 'per K.L.M.' with instructional 'Onvoldoende Gefranking/ Insufficiently Prepaid' in violet with octagonal 'T/ Centimes' hand-stamp and endorsed '21', bearing 'Dutch Rule Restored' SG D495, 20c blue mixed with United States of Indonesia SG D576, 2 1/2c on 50c yellow applied and tied by Medan receiver '29th April' on face.
Ex Paul Bulterman's Indonesia postage due collection.