“We thought it was lost forever. This could be the guitar that sets a new world record”: John Lennon’s missing Help! Framus acoustic has been found in an attic after 50 years – and it could become one of the most expensive guitars ever sold

The 12-string acoustic guitar was used on a number of classic Beatles tracks, and is tipped to rival Kurt Cobain’s $6m Martin D-18e when it hits the auction block next month