Great Britain 1915 1s bright blue "Postage due" (Somerset House printing) imprimaturs, SGD8varGreat Britain 1915 1s bright blue "Postage due" (Somerset House printing) imprimaturs, SGD8var. A very fine unmounted mint, with full original gum, bottom marginal pair of imperforate imprimaturs, each stamp with a "BPMA" handstamp on reverse. Some light gum wrinkling as was prevalent across the whole sheet. A scarce King George V Postage Due pair from the first approved printing sheet. Exceptional provenance as it was released from the British Postal