A five-year search by the manufacturer of the instrument that was aided by a husband-and-wife team of journalists helped reunite The Beatles star with the distinctive violin-shaped 1961 electric Höfner that went missing a half century ago and is estimated to be worth 10 million pounds ($12.6 million).

McCartney had asked Höfner to help find the missing instrument that helped launch Beatlemania across the universe, Scott Jones, a journalist who teamed up with Höfner executive Nick Wass to track it down, said Friday. ...

The estimated value of the instrument is based on the fact that a Gibson acoustic guitar Kurt Cobain played on MTV Unplugged sold for $6 million (4.7 million pounds), Jones said. But it held almost no value during the past half century.

“The thief couldn’t sell it,” Jones said. “Clearly, the Guest family never tried to sell it. It’s a red alert because the minute you come forward someone’s going to go, ‘That’s Paul McCartney’s guitar.’”