1937 MAIL BIRMINGHAM TO ARGENTINE 5S SEAHORSE X 2/SAMPLE RATE? Envelope (124 x 279) with pair of 5s Seahorse (SG451) and pair of 1s photogravure (SG449) one with corner fault, cancelled BIRMINGHAM date stamps 26 MCH 37 with ms "VIA FRANCE". Apparently this 12s rate paying trade sample packet rate via the French route - 12s = 12 oz. (Ref 104918).