North Borneo SG 218a 1918 Red Cross 4c+2c block of 4 Error Surcharge INVERTED 2 x U/M

1918 (Aug) Red Cross 4c+2c scarlet block of 4 Error SURCHARGE INVERTED (with additional inverted albino impression on reverse) mint large part o.g. with the lower pair remaining unmounted a fine and rare multiple from the one sheet that existed. SG 218a cat 1800++ pounds