Ronald Baldwin, aged 89, first came across the card in the 1930s, when he bought a pile of books for a shilling. Among them was a mysterious postcard from the doomed ship he had found amongst them. Simply signed Bert, it had puzzled him down the decades, so he decided at last to root it out from an old shoe box and identify the writer from among the 2,200 people who set sail on the ship from Southampton in April 1912. The postcard was addressed to Mrs W H Taylor, Castle Cary, so Mr Baldwin travelled from his home in the New Forest to the town's library to search through 1912 copies of the local newspaper. He eventually discovered that Mrs Taylor was born Ida Mary Pitman - sister to Titanic third officer Herbert John Pitman, who lived in the town and is buried at nearby Pitcombe. He checked the handwriting with the British Titanic Society, which confirmed it was identical to Pitman's copper-plate style.
Now the historic postcard, bearing a close-up of the Titanic nearing completion in Belfast, is expected to sell for £32,000 when it is auctioned by Wiltshire firm Henry Aldridge and Son at the society's annual convention in Southampton on April 14.
Mr Baldwin said: "I am fascinated by Sherlock Holmes, which prompted me to put on my deerstalker and go on the trail of Bert all those years later. Actually, there was a whole postcard album among the bundle of books. It must have belonged to Mrs Taylor because there were lots addressed to her in Castle Cary. But I was not interested in postcards and the album has long since disappeared. I just kept a few that were to do with the Titanic and forgot about them for decades."
Auctioneer Andrew Aldridge said: "If only he had kept the whole album - it would probably be worth a fortune.'