A Dublin restaurant manager has found a 70-year-old signed copy of John F Kennedy’s Harvard thesis, worth up to €5,000, in a box of old books he bought for €8 at an auction.

Jon Foley discovered Why England Slept, published in 1940, when the former American president was aged just 23, in a collection of books that belonged to Anne Moen Bullitt, the Kildare-based daughter of America’s first ambassador to the Soviet Union.

Bullitt, whose father William C Bullitt also served as the US ambassador to France, died in a Dalkey nursing home in 2007. Her mother was Louise Bryant, the famous American radical who was played by Diane Keaton in the 1981 movie Reds, which also starred Warren Beatty.

Foley was browsing at one of Herman & Wilkinson’s weekly auctions in Rathmines, Dublin, last December when he spotted the box of old political books. “I was on the look-out for a wooden table for my mother, but I started thumbing through the books because they looked interesting. I’m into politics,” he said. “When the lot came up I bid €2. Another guy bid €4 and I eventually got it for €8.”

It was only afterwards that Foley opened Why England Slept and discovered Kennedy’s handwritten note inside the front cover. It read: “To Ambassador Bullitt. With happy remembrance of a very pleasant two months. With thanks and sincere best wishes. Jack Kennedy.”

The former president had spent about eight weeks in Paris with the ambassador, a friend of his father Joe Kennedy. It was part of the young JFK’s tour of Europe in the lead-up to the second world war in 1939.

“I thought I was dreaming when I read the inscription,” said Foley. “I didn’t even know Kennedy had written a book, let alone that I’d picked up an autographed first edition for less than a tenner.”

Other signed first editions of the book, an expansion of Kennedy’s college thesis on the causes of the war, are on sale on rare book websites for about $12,500 (€9,700). The edition acquired by Foley is missing its dust jacket, but is still worth about €5,000, according to one Dublin rare books expert, and he could double that sum if the dust jacket is found.

“It is a lovely find,” said Eamonn De Burca of De Burca Rare Books in Dublin. “The warmth and the intimacy of Kennedy’s inscription would add to its value, as well as the fact he signed it two decades before he became president.”

Ray Wilkinson, a director of Herman & Wilkinson auctioneers, said he had not checked the contents of the box of books before selling them to Foley.

“I didn’t do the sorting. We got about 50 or 60 boxes of Bullitt’s books from another auctioneer to sell. But we heard afterwards a valuable book had been among them,” he said.

He declined to name the auctioneer who had consigned the books. “I don’t want to implicate anyone else,” he said.

James O’Halloran, the managing director of Adam’s, the auctioneer, which has been handling the sale of most of Bullitt’s possessions, said: “These sorts of things happen. The odd valuable thing slips through the net. But that’s why people keep going to auctions in the hope of a lucky break like this.”

Foley plans to reunite the book with an original dust jacket and get it revalued in America in four years’ time, the 50th anniversary of Kennedy’s assassination. “It’ll probably be worth even more by then,” he said. “I can’t believe my luck.”

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