The man turned it down because his daughter already had a recorder,Blackfriars crown court was told.
The previous day, Irish traveller John Maughan, 40, had used two teenage accomplices to act as decoys so that he could snatch the instrument from under the nose of acclaimed musician Min-Jin Kym as she ate in a Pret a Manger atEuston station.
Not realising what they had, the thieves were spotted researching the violin in the internet café in Tottenham Court Road the next day.
Miss Kym, 32, who is signed to record label Sony BMG, bought the violin 10 years ago for £750,000. It is valued at £1.2 million but her insurance only covers the £750,000 she paid for it.
The instrument, which was made in 1696, was in a black case that also contained a Peccatte bow worth £62,000 and another made by the Bazin school valued at more than £5,000.
Prosecutor Mark James-Dawson said: “She is one of the top violinists in the world and she has this instead of a house, instead of a car and she gets to a violin of this value by trading up as one would a mortgage as she has become more successful.”
The violin, which has not been recovered, was stolen on November 29 and the thieves were arrested four weeks later after Maughan was identified following an appeal on Crimewatch.
The court heard Dublin-born Maughan had more than 40 aliases, 26 different dates of birth and more than 65 convictions, 59 of them for theft.
Today the thieves all pleaded guilty to a single count of theft but Judge Deva Pillay adjourned sentencing and warned them: “All options are open. Inevitably there is going to be, I suspect, one of custody.”
Maughan was remanded in custody while the teenagers, who were not forced to stand in the dock for the hearing, were released on bail until they are sentenced on a date yet to be set.
Detective Inspector Andy Ross, of the British Transport Police, said: “It’s possible the instrument will be offered for sale within the antique or musical trade and we ask anyone who has any knowledge of the violin’s whereabouts to come forward so it can be returned to its rightful owner.”