Estimated to fetch more than £600,000, auctioneers believe the 12-string acoustic guitar used in the recording of The Beatles' Help! album and film, could set a new world record as "the highest-selling Beatles guitar".
The Pointless host's hit debut novel - which is being turned into movie - follows a group of friends in a retirement home who solve cold cases for fun, but become entangled in a real murder.
Nine of the 10 authors nominated for the Jean Stein book award - which carries a prize of $75,000 - withdrew their work, and the money will now be donated to the Palestine Children's Relief Fund.
Anne Hathaway - who has since won an Oscar, Emmy, Golden Globe and BAFTA - described the chemistry test as "gross" but admits she felt under pressure to avoid being labelled as "difficult" so pretended to be "excited" about it.