What would turn out to be the final glorious incarnation of Jaguar's fabulous 'XK' series of sports cars arrived in 1957.

As its nomenclature suggests, the XK150 was a progressive development of the XK120 and XK140, retaining the same basic chassis, 3.4-litre engine and four-speed Moss transmission of its predecessors while benefiting from a new, wider body that provided increased interior space and improved visibility courtesy of a single-piece wrap-around windscreen, replacing the XK140's divided screen.

Cleverly, the new body used many XK120/140 pressings, the increased width being achieved by means of a 4"-wide central fillet.

A higher front wing line and broader radiator grille were other obvious differences, but the new model's main talking point was its Dunlop disc brakes.

Fade following repeated stops from high speed had been a problem of the earlier, drum-braked cars, but now the XK had stopping power to match its prodigious straight-line speed.

Introduced in the spring o...