The stamps are all unmounted mint with the top two rows perfectly normal, the lower three rows show increasing signs of non-perforation. The bottom row of perforations on the middle row shows some 'blind' perforations and to the left hand side (when viewed from the front) the perforations are indented but not piercing the paper. This situation persists for the lower two rows, with the bottom row in particular being completely imperforate between the stamps and lower margins for all five stamps and also with the vertical perforations becoming less indented as they progress down the sheet. The Pierron 'Errors' catalogue of Great Britain lists a single stamp as F616IMa 'Imperforate between stamp and bottom margin' which catalogue £500. The piece on offer has four examples of this stamp plus a further stamp that is torn and thus discounted by us. In addition this impressive block contains the five stamps in the fourth row down that are to a large extent visually imperforate, although more accurately described as 'blind' perforated examples.
