i.e. 240 stamps of each value exist. The De La Rue factory in Hong Kong burned down during the early part of the Twentieth Century at which time much of the archive rightly or wrongly appeared on the market via a Hong Kong stamp dealer, including the plate proof sheets.  The printing plate number 1 appeared twice on each sheet, in the upper right hand margin and lower left hand margin. This would mean that only two ‘sets’ of corner plate blocks exist. Furthermore, we understand that at least one value is known in a plate number single and therefore this would rule out the potential existence of a second set. Accordingly we consider to the best of our knowledge the set of corner plate blocks of four we are offering now is UNIQUE IN HONG KONG PHILATELY.  All of the blocks have some foxing to reverse which does not detract from an impressive facial appearance. Although the printing was on un-gummed paper, some of the values, notably 2c, 6c, 24c, 30c and 96c (all have larger margins than the others), clearly show that gum has been applied at the edges of the margins, presumably to facilitate their display on the walls of the printing works. 

We offered a complete set of 9 ‘singles’ of this issue through this catalogue about 5 months ago and they sold immediately with several disappointed purchasers. We have seen over the years a few sets offered in imperforate pairs, but we have never previously seen blocks of four in any condition and nothing, which comes close to imperforate corner marginal plate blocks of four. Rare, probably unique.