Kavel 1279

GREAT BRITAIN 1913, unused S.G. 351 var., ½d. green showing distinctive variety "shifted and partial double impression in upper left part of stamps", clearly separated by a diagonal line in the paper structure due to shrinked paper during printing process, leading to a clear misalignment of this part of the stamp and clear double impression at upper left corner, mint o.g. extremely rare and attractive variety, not listed in SG spec., possible unique, in folder