For some reason, there exists an extraordinary concentration of pseudonyms in works published as card-game rule-booklets. Cavendish wrote around twenty for De La Rue. Professor Hoffmann wrote around sixteen for Goodall. Captain Crawley wrote several. A fair number of other pseudonyms appeared, including Rawdon Crawley (Captain Crawley’s son, though I believe Captain Crawley also wrote under the name), Camden, Jack Smarte, Viator, and others.
One such pseudonym was Nemo. I do not know who Goodall’s Nemo was, but Nemo was the author of Kuhn Khan, the first edition of which was probably dated 1912. That is shown as the date of the copy (from Jessel’s collection) in the Bodleian Library.
Below is shown the cover of a 1913 copy that presumably originated in a Kuhn Khan game-set, because it is covered in a an outer material outside of the normal heavy-paper covers (in this case, black material of an unidentified character). The copy shown was an expanded edition. It included additional material by R.F. Foster.
Mike Goodall’s 2000 book on the Goodalls shows that a wide variety of materials were used in the manufacturing of the Goodall card-game sets. Among the materials he shows are (among others):
Long grain leather
Imitation long grain leather
I have seen card-game rule-booklets with the outer covers (material outside of the heavy-paper covers) in a variety of materials. My assumption is that such booklets normally accompanied a boxed card-game set, and that the outer covering-materials ordinarily matched one of the materials on the set.
Below is shown the inside front-cover and title page of a 1913 edition.