It's the anniversary of the Battle of Britain and we're celebrating the Supermarine Spitfire - the single-seat fighter plane credited with winning against Nazi Germany's Luffwaffe airforce in the first major campaign ever to be fought entirely by air forces.

The Spitfire was hugely popular in many Allied countries during and after WWII, and there were eventually 24 marks of the plane and numerous sub-variants in use up until it was retired in 1955 as new jet engines phased out propeller-powered aircraft.

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A restored Supermarine Spitfire takes to the skies

Today, there are 235 Spitfires remaining across the world, and only 52 of them are airworthy.

A company called Avspecs in New Zealand specialises in restoring vintage and wartime aircraft, making each plane as authentic and accurate as possible, so that it will fly and be as good as a brand new plane straight from a factory.

Once restored, Spitfires sell for a minimum of £2m ($3.4m) each, while wrecks can be obtained for roughly about £700.

Check out the amazing photographs from Avspecs' award-winning Warbirds Restoration workshop in Auckland, where three different Spitfires, ranging from a mk.5 to a mk.14 are painstakingly being restored. You can read our interview with Avspecs' owner Warren Denholm about restoring Spitfires here.

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Repairing the wing frame
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Close-up of a Spitfire wing
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Working on the body of the plane
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A sneak peek at the Avspecs' Warbird Restoration workshop
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Sanding down a wing
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Fitting casing over the engine of the plane
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A close-up at the tail frame of the Spitfire
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The cockpit of a Spitfire
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Inside the cockpit
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Inside the cockpit
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Fixing the Spitfire's landing gear
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Working on the propeller
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Building parts for the Spitfire
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Painting the Spitfire wing
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The Spitfire starts to come together
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Working on the Spitfire
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Close-up of the Rolls-Royce engine
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Testing out the Spitfire
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Getting there
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Preparing the pilot for take-off
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Off we go!
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The majestic Spitfire flies again
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The team behind Avspecs' Warbird Restoration of the Spitfire