Douglas Adams writes:

To the consternation of many of my biblio-friends I took up coin collecting about 5 years ago after the rediscovery of my childhood collections that had survived intact in my mother's attic. Thethought that two collections, two intense interests, could coexist seemed unfathomable to them.

Coin collectors, however, have no doubt of the importance of books in their endeavors as the tutelage given all budding numismatists is "buy the book before the coin." I myself have, and continueto follow this sound advice and have begun to build a small numismatic library, but this seems not to count among my more literary minded friends. I must continually stress to my biblio-friends thata book is a book and that my love for books has not diminished in the least, even though I may divert some of my resources to the numismatic collections that would have in the past been directed intothe literary collections I still find I'm able to enjoy my paper collections and metal collections equally.

I had not thought it possible to merge my two interests - coins and books - seamlessly into each other but I've discovered a few instances where my two hobbies joyously collide:

Mark Hofmann, a book and antiquities dealer operating in Salt Lake City, began his illicit career in his young teenage years by "improving" coins, whereby he would add mintmarks making a commoncoin rare. Later, he progressed to forging Mormon scrip money and then documents and manuscripts relating to The Church of Jesus Christ of Latter-day Saints.

Hofmann evidently became quite proficient in creating numismatic rarities and in fact operated as a teenage dealer under the business name of "Mark's Mint Mistakes". In 2002,Hofmann made claim to creating the controversial 1959-D Lincoln Cent Mule, which notably passed Treasury Department inspection but remains an anomaly.

According to a New York Times article, Hoffman's forgeries were the most sophisticated ever seen, fooling nearly all the top forgery experts in the country. Charles Hamilton, the preeminentdocument dealer and expert in forged manuscripts, wrote that "Mark Hofmann was unquestionably the most skilled forger this country has ever seen":

To read the complete article, see:
Collections in Collision - Coins & Books / Books & Coins(https://www.cointalk.com/threads/collections-in-collision-coins-books-books-coins.308602/)

To read about the 1959-D Mule Lincoln Cent, see:
The Mystery of the 1959-D Mule Lincoln Cent(https://www.pcgs.com/news/the-mystery-of-the-1959-d-mule-lincoln-cent)

To read the earlier E-Sylum article, see:
BOOK REVIEW: THE JUDGMENT OF EXPERTS (http://www.coinbooks.org/v20/esylum_v20n54a06.html)