It is indeed a creation of Sam Clemens, marketed in a number of different
formats and covers, plain and sometimes quite elaborate, over a number of
years.  This invention actually made money for Clemens, perhaps having the
byproduct of reinforcing his self-image as astute businessman, a delusion
that would lead to disaster in the form of the Paige typesetter.  Slote,
Woodman & Co. was a New York Publisher and, if memory serves me, the
publisher of the 1871 "Mark Twain's Autobiography and First Romance."
(That's a paraphrasing of the actual title, a slim volume illustrated by
Thomas Nast).  The Self-Pasting Scrap Book is one of the more accessible
pieces of Twain ephemera for collectors, often showing up in ebay auctions.

Martin Zehr
Kansas City, Missouri