Great Britain - 1840 1d Penny Black Official VR, a spectacular negative glass cliché from a negative master matrix. The Penny Black has never been mentioned in the literature dedicated to the work of Jean de Sperati, this being a major discovery of one of the most iconic stamps of worldwide philately. (Image)

Great Britain - 1840 1d Penny Black Official VR, glass support cliché in black, numbered and registered at base "8/1" & "c.8". The Penny Black has never been mentioned in the literature dedicated to the work of Jean de Sperati, this being a major discovery of one of the most iconic stamp of worldwide philately. Unique. (Image)

Great Britain - 1840 1d Penny Black Official VR, black impression on celluloid; a unique part of a hitherto unrecorded reproduction by Sperati. (Image)

Great Britain - 1880 2s Victoria, dark brown glass support cliché in negative impression, position KJ (four positions were manufactured by Sperati). One of six clichés recorded, being unique in negative. (Image)