Ex-Beatle Paul McCartney learned his first chords on the guitar, which was owned by his best school friend in Liverpool, Ian James.
But now Mr James, 64, who lives in Ormskirk, Lancashire, is selling the guitar to help raise money for his retirement.
A letter of authenticity from Sir Paul accompanies the guitar, which says: "The above guitar belonging to my old school pal Ian James was the first guitar I ever held.
"It was also the guitar on which I learned my first chords in his house at 43 Elswich Street, Liverpool 8."
Paul McCartney mentioned Mr James in "The Beatles", a biography by Hunter Davies.
The lot to be auctioned also contains a photo taken by Paul McCartney of a young Mr James playing the guitar in 1957 and a photo of the former Beatle playing the guitar in his office earlier on this year.
