Donald Healey's eponymous company built a prototype two-seater sports car for display at the 1952 London Motor Show based on Austin A90 Atlantic mechanicals and sporting a notably sleek body designed by Gerry Coker and built by Tickford.

It was dubbed the 'Healey Hundred' (a moniker chosen to reflect the car's ability to reach the magic 100mph), and, subject to a suitably encouraging response, Healey planned to build production versions in-house at his factory in Warwick.

As things transpired, not only did the Ice Blue prototype more than impress the public, but also so excited Austin's Managing Director, Leonard Lord, that he struck a deal to build the car in volume at Longbridge which became known as the Austin-Healey 100/4 (BN1) The 100/4's chassis was a departure from the company's previous backbone designs and comprised a pair of three-inch square box-section side members running the length of the car, some 17 inches apart.

These were braced by parallel and cruciform cross-memb...