1923 UNDERPAID MAIL LONDON TO FRANCE WITH FRENCH POSTAGE DUE. Envelope with letter from 'The Royal Institute of British Architects' London to the Imperial War Graves Commission, St. Omer, France with KGV 1½d brown postal stationery embossed cancelled 'LONDON' MAR 7 1923. Postage underpaid with 'T/50' chargemark and French 50c postage due cancelled 'ST.OMER' 9-3-23. (Ref 97898).
