GUERNSEY 1991 (VARIETY) 21P KING'S MILLS BLOCK WITH IMPERF RIGHT MARGIN
21p King's Mills lower right marginal block x 12 imperforate between stamps and right margin. A perforation skip further results in the lack of part of the horizontal perforations from the rightmost column of stamps. An amazing multiple. Just 10 stamps in total are believed to have been affected thus. Fresh and fine. Mint never hinged. SG310bvar; SC453var; GGY610a