Ceylon 1921-32 3c slate-grey, script watermark, variety SG340aCeylon 1921 32 3c slate grey, script watermark, variety WATERMARK SIDEWAYS, SG340a. A fine unmounted mint, with full original gum, block of 4 from lower right corner of upper right pane, with part interpane margin below. Lightly toned gum, which is inconsequential as very fine appearance with fresh colour, and the watermark variety clearly visible in the right margin from the face. A major keyplate unique rarity. To the best of our knowledge this the