Free Package and Postage on this item. The Spitfire is the most famous British fighter aircraft of all time, designed by R.J. Mitchell, and based on his very fast, pre-war seaplane, the S6. The Spitfire MK1 was powered by a 1,030-hp Rolls Royce Merlin engine and had a top speed of 365 mph. It was armed with 8 x .303 Browning machine guns mounted in the wings, which proved very effective against both fighters and bombers. This highly detailed Spitfire model, measuring 5cm wide, is made from lead-free pewter and is supplied on a quality key-chain.