The stamp is accompanied by two "Genuine" certificates issued by the Expert Committee of the Royal Philatelic Society, London: Certificate No. 18,796 (17 October 1935), signed by Thomas William Hall, and Certificate No. 217,796 (17 March 2014), signed by Christopher Harman.

The stamp was also examined by Thomas Lera, the Winton S. Blount Research Chair of the Smithsonian National Postal Museum, on 17 April 2014, and several photographs taken by Mr. Lera are reproduced in the catalogue.

Andrew Hunter (1856–1873), original recipient of the mailed stamp;
Louis Vernon Vaughan (1873);
Neil Ross McKinnon (1873–1878);
Thomas Ridpath (1878);
Philipp de la Rénotière von Ferrary (1878–1920; purple trefoil on reverse);|
Government of France (1920–1922);
Arthur M. Hind (1922–1933; manuscript “H” on reverse; cloverleaf "AH" handstamp on reverse);
Ann Hind Scala (1933–1940; perhaps a seventeen-point star handstamp on reverse used to obscure the cloverleaf of her husband);
Frederick Trouton Small (1940–1970; comet handstamp on reverse; also initialed in pencil “FK” by his agent Finbar Kenny);
Irwin Weinberg and Associates (1970–1980; pencil “IW” on reverse);
John E. du Pont (1980–2014; pencil “JEdP” on reverse)

Selected Exhibitions:
1923 London International Stamp Exhibition May 14–28
1926 New York International Stamp Exhibition October 16–23
1929 Le Havre, France, Exposition Philatélique Internationale May 18–26
1930 Boston, American Philatelic Society National Exhibition August 11–16
1940 New York World’s Fair, British Pavilion May
1947 New York Centenary International Philatelic Exhibition May 17–25
1956 New York Fifth International Philatelic Exhibition April 28–May 6
1963 Melbourne International Philatelic Exhibition October 6–12
1965 London Stanley Gibbons Catalogue Centenary February 17–20
1970–1980 Irwin Weinberg toured the stamp extensively including trips to England, Japan, Switzerland, France, India, Czechoslovakia, Germany, SPain, and Canada
1986 Chicago Ameripex International Stamp Exhibition May 22–June 1 (Part of the British Guiana exhibit by “Rae Mader," which won the Grand Prix)
1987 Perth, Australia, CUP-PEX National Philatelic Exhibition January 31–February 8

The One-Cent Black on Magenta is unique—the sole surviving One-Cent of the entire 1856 issue produced in Georgetown, British Guiana. The survival, rediscovery, and subsequent chain of ownership of the unique example of the One-Cent Magenta is just as serendipitous and captivating as the story of its creation. The significance of the stamp was first recognized by the great philatelist Edward Loines Pemberton, who declared as early as 1878 that the “ONE cent, red, 1856!!! [is] as genuine as anything ever was.” And just thirteen years later, The Philatelic Record formally acknowledged that the British Guiana was unique: “This is without doubt, in our opinion, the rarest stamp in the world, in its solitary grandeur.”

More than a century and a half after its creation, this stamp remains the ne plus ultra of the world's most popular collecting pursuit.