John Lennon's toilet and one of his rarest albums will be among the highlights of an auction of Beatles memorabilia next weekend.
A mono-sound copy of Two Virgins, which he recorded with Yoko Ono, is expected to fetch at least £2,500.
When the avant garde LP was released in November 1968 it was notable for being sold in brown paper bags because the sleeve controversially featured a naked picture of the famous couple on the cover. Although a limited release of 5,000 stereo versions of the album were available in shops, fans had to write to the record label to purchase a mono copy.
The exact number of mono copies sold is not known, but auction organisers say it is likely to be a "couple of hundred".
The sale, part of the 33rd annual Beatles convention in Liverpool, is attracting record levels of interest.
Bids are also being invited for Lennon's toilet from Tittenhurst Park, his Berkshire home between 1969 and 1972.
Lennon told a builder, John Hancock, to keep the porcelain lavatory and "use it as a plant pot" after he had installed a new one. It was stored in a shed at Hancock's home for 40 years until he died recently. The toilet is estimated to fetch £750 to £1,000.
The auction organiser, Stephen Bailey, said: "The toilet might be worth something, and it might not, but it is certainly one of the more unusual items we've sold."
Bailey, manager of the Beatles Shop in Liverpool, added: "I have only ever come across two other mono copies of Two Virgins before so that will be the one to watch. Even at the end of the sixties, during such a bohemian period, the picture of a naked couple on the album cover still caused a great deal of scandal.
"The stereo version sold relatively few copies at a time when any one of the Beatles could easily have shifted hundreds of thousands of records.
"It must be one of the rarest Beatles solo albums to come up for auction."
A small harmonica that belonged to Lennon's son, Julian, is also up for auction. It was also given to Hancock by Lennon, who asked him to take it home as "Julian was driving him mad with it".
Lennon told Hancock he would tell Julian it had been lost. The harmonica is expected to fetch between £750 and £1,000.
Fans of Sir Paul McCartney can bid on a black and white photograph taken of the budding star outside his family home, 20 Forthlin Road, Liverpool, when he was aged about 21. The estimate is £375-£400.
Other lots include an early concert ticket from 28 September 1962, when the Fab Four played the Royal Iris Mersey Ferry. It is valued at £2,500.
A full set of Beatles autographs could go for £1,000-£2,200.
Less expensive lots include a 1966 ticket for Mathew Street's Cavern Club, where the band made their name, which is expected to fetch between £60 and £100.
Mass-produced memorabilia created at the height of the band's fame, such as Irish linen teatowels and China plates, are valued at around £20.
Bailey said interest in the Beatles was on the rise as fans prepared to celebrate a series of 50-year milestones, such as the band's first performance in Hamburg, Germany.
The auction, which includes 295 lots, will take place next Saturday at the Liverpool Institute for the Performing Arts.