A restored Spitfire that was built in Southampton will be up for auction at Christie's

Now this Spitfire, P9374, to many a thing of beauty but also an iconic war machine which helped save Britain in 1940, and ultimately to win the Second World War, will be offered in an auction at Christie's tomorrow, where it is expected to fetch up to £2.5million.

Unearthed in the sands of Calais beach, the aircraft was crash-landed during the Second World War.

Initially, the identity of the aircraft remained a mystery, but following its recovery by the manager of the nearby Hoverport in January 1981, the Spitfire was identified as P9374, an early Mk 1 version of Supermarine’s finest creation.

When the aircraft came down the pilot radioed that he was uninjured and to tell his mother, “I’ll be home for tea!”

One of only two original Mark 1 to still be flying, the legendary fighter was one of a batch of 138 Spitfires built under Air Ministry contract at Supermarine’s Woolston works and delivered to the RAF on March 2,1940 before arriving at 92 Squadron at RAF Croydon four days later.

At that time this renowned fighter squadron was engaged on Home Defence duties.

During Spitfire P9374’s service with 92 Squadron it is known to have been flown by at least eight different pilots, including Sergeants Barraclough, Eyles and Fokes, Pilot Officers Bryson, Saunders and Williams and Flight Lieutenant Green.

It was Pilot Officer Williams, however, who ‘blooded’ P9374 in action on May 23 when he claimed a Me 110 destroyed over the French coast.

It is almost certain to have been flown at some stage by the Commanding Officer of 92 Squadron, Squadron Leader Roger Bushell, later ‘Big X’ of the Great Escape fame.

Another man who piloted P9374 was Flying Officer Peter Cazenove pictured below, who was flying the aircraft on May 24, 1940 in what was his first and last combat sortie of the war.

Records show that P9374 had a total flight time of 32 hours and 5 minutes at the time of its loss.

Flying from RAF Hornchurch in Essex, 92 Squadron was covering operations on the ground in what would ultimately see the fall of Calais to German troops.

During this early morning sortie P9374 was hit by what is thought to have been a single bullet fired from a Dornier 17-Z bomber which holed the Spitfire’s coolant system.

With an overheating engine, and with no realistic hope of returning across the English Channel, Cazenove made a wheels-up forced landing at low tide on the beach near Calais.

Before executing what was a perfect belly-landing Cazenove radioed that he was OK, adding: "Tell mother I’ll be home for tea!"

From where he had landed he made his way into Calais town and fought a rear-guard action with the army before the town eventually fell to the attackers and he was taken as a POW.

During his time as prisoner Cazenove made several escape attempts but was later incarcerated at Stalag Luft III from where the Great Escape was mounted.

German soldiers posing with the shot-down Spitfire

Cazenove became involved in forging documents for the escapers, but of the many scheduled to break out of the tunnel he was last on the list.

His physical size led to fears that he would become stuck in the tunnel, but this may well have saved his life as the escape was discovered before Cazenove’s turn came.

Of those who escaped and were recaptured, 50 were executed by the Gestapo. Among them was Cazenove’s CO, Roger Bushell, who had been shot down and taken prisoner on 23 May 1940.

The occupying Germans did not attempt to recover the wreck of P9374 and on successive tides the Spitfire sunk deeper into the sands until it had vanished from sight.

Its re-emergence in 1980 is thought to have been the result of nearby sand dredging related to the operation of cross-channel hovercraft.

Despite its long immersion in the sand many of the recovered components, including the engine and machine guns, were found to be in remarkably good condition.

Sadly, it transpired that Peter Cazenove had died shortly before the recovery of his aircraft. Not long before dying he had remarked: "I wonder what happened to my Spitfire and I wonder if anyone will ever find it?"

The Spitfire’s Browning .303 machine guns were so well preserved they operated perfectly after being cleaned and oiled.

Post-recovery, the Spitfire went first to the Musée de l’Air at Le Bourget, Paris, from where it was acquired by a French collector, Jean Frelaut, in 1981. It was from Frelaut’s estate that the aircraft was acquired by the present owners, Mark One Partners, in 2000 and placed on the British Civil Aircraft Register as G-MKIA that year.

There followed a meticulous reconstruction, the motto for which was surely ‘attention to detail’.

This process which involved a 100 per cent faithful following of the build and fit, down to sourcing correctly dated instruments and equipment.

If a piece of kit was the correct type but, say, dated 1940 or 1941 then it was discarded in favour of a correctly dated item. This meticulous policy even ensured that the ammunition for the guns is correctly dated.

Where possible, original components from the wreck of P9374 were included. The fuselage ‘tube’ was constructed by Airframe Assemblies on the Isle of Wight, not far from its original birthplace, with the wings being built at Duxford in 2007 by the Aircraft Restoration Company. The fuselage and wings were married up at Duxford in July 2008 where P9374 was fitted out, painted and finished.

Engine and propeller had been re-engineered and constructed by Retro-Track & Air of Cam, Gloucestershire, and successful ground-runs of the installed engine were conducted in June 2011. Many components from the original engine of P9374 were incorporated into the build.

The completed aircraft was first flown at Duxford on September 1, 2011 by John Romain who later remarked of P9374: “You don’t get into a Spitfire, you put it on. This is a fantastic restoration. to be justifiably proud of The Spitfire P9374 is a truly lovely aircraft, and she flies beautifully.”

The Vickers Supermarine Spitfire Mk.1A – P9374/G-MK1A aircraft went on display outside the Churchill War Rooms in London before the sale at Christie’s.