The section of fuselage was salvaged from a farmer’s field where the Messerschmitt plane, piloted by Nazi party deputy leader Rudolf Hess, had crashed.
The deputy führer had flown alone from Germany on 10 May 1941 in the hope of bringing Britain to the negotiating table for secret peace talks.
In a letter to Hitler, Hess said he planned to meet the Duke of Hamilton, whom he wrongly thought was opposed to war with Germany.
When he got low on fuel he bailed out, parachuting into a field at Floors Farm in Eaglesham, just south of Glasgow, while his plane crashed in a neighbouring field.
Dave McLean, the foreman at Floors Farm, captured Hess, who identified himself as Captain Albert Horn and had suffered a broken ankle while landing.
After handing him over to the police, Mr McLean cycled to the crash site and, knowing the plane would soon be recovered, hid several parts from the wreckage in nearby bushes.
He retrieved them later using a tractor and gave a section of the plane’s fuselage to 18-year-old farmhand Stanley Boyd as a souvenir. Mr Boyd sold the fuselage in the 1960s to the former assistant secretary of the Battle of Britain Association, who then passed it to the War Museum.
It is tipped to fetch £3,000 when it goes under the hammer at auction house Bonhams.
Mr Boyd later recalled the events in a previously unseen letter, which is included in the auction. It reads: “His [Hess’s] fighter plane had crashed in the next field which was Bonnytons Farm and Dave had gone over on his cycle and hidden a few souvenirs in the bushes.
“The whole wreckage was taken away by the army maintenance unit from Carluke and nothing was left. Dave went back later in the tractor and retrieved the items of which he gave me the section you are having for your collection. When we all found out later that the pilot was the German deputy leader under Hitler, we really couldn’t believe it.”
After his capture, Hess was kept in Britain as a prisoner of war until his trial following Germany’s surrender on 8 May 1945.
Hess was found guilty of war crimes and sent to Spandau prison in Germany to serve a life sentence. On 17 August 1987, then aged 93, Hess hanged himself in the prison’s summerhouse using an electrical cable.
Tom Lamb, a historian at Bonhams, said: “The story of Rudolf Hess’s strange flight to Britain in 1941 is well known but the story of Stanley Boyd, the farmhand who ended up with this section of fuselage, has never been told before.”
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