cover 1895 (c.) 5c. brown, forward portion of stationery reply card (1889 issue) addressed to Leopoldville, cancelled by superb strike of the large black circular "DISTRICT DU KASSAÏ/flag" cachet (unlisted by both De Cock and Du Four), a few very faint stains, slight thins on front at top-left and on reverse at top, rare and most unusual. Photo