Netherlands 1929 // 1937 group of 6 airmail covers: Two Registered Airmail Covers from Amsterdam Netherlands to Calcutta Netherlands Indies, postmarked in September & December, 1929. Transit and arrival cds on reverse G.P.O. Calcutta; 1935 Hotel cover airmail heavily franked for 30gr. Airmail etiquette with a handstamp KARACHI / CANCELLED / 26 JUN 35. cds on reverse; KLM 1935 Batavia Netherlands Indies Airmail with  a handstamp KARACHI / CANCELLED / ; 1936 Netherlands indies Cover addressed to Lady Ezra .