According to many historians, John Lennon bought his first record in April or May 1956 at the age of 15. It was "Rock Island Line", a skiffle-hit for Lonnie Donegan. Other records that he bought around that time were "the Ying-tong Song" by comedy group The Goons, and Elvis Presley's Hound Dog.
John was so captivated by the music that he dragged his aunt mimi to the shops to buy him a guitar. When she refused, he bought a mail-order Gallotone Champion which can be seen on the famous picture of The Quarrymen playing at Saint Peter's church (the first time Paul saw John playing and probably the most important day in their lives). According to the magazine (Reveille) it was "guaranteed not to split". John had the guitar delivered at his mum's house whereJulia Lennon thought him a couple of 5-string chords (the reason why John didn't use the sixth string and left it intentionally slack. It was this guitar that John used in his first band (The Black Jacks) with his friend Pete Shotton.
There is a really nice story about what happened to the guitar. It broke at some point in 1958 and ended up in Aunt Mimi's house after John moved out. When John was murdered in 1980 Mimi gave it to a family friend who had a disabled son. After the boy died, the guitar ended up with another disabled friend and was sold at an auction by Sotheby.
How do we know the guitar is indeed the real deal? Well, interestingly Sotheby's asked fellow Quarrymen member Rod Davis to identify the guitar. He remembered that there was a spot of blood inside the guitar from where John cut the skin of his finger...and sure, the spot was still there!
Eventually the guitar sold for 250,000 dollar, with part of the proceedings going to a school for Liverpool disabled musicians. And the current owner displayed it at the Boston Museum of Fine Arts during the winter of 2000/2001 for the "Dangerous Curves" exhibition