Mechanicals were attached to an all-new frame. Designed by Harold Beach, it replaced the DB2/4's multi-tubular space frame considered incompatible with Touring's superleggera-style body construction.

Underneath, the trailing-link independent front suspension gave way to unequal-length wishbones. At the rear, the DB4 sported a live axle located by a Watts linkage instead of its predecessor's Panhard rod.

The DB4 was available only as a closed coupe until September 1961, when the convertible version was unveiled at that year's motor show. Priced at £4,449, it was £250 more expensive than the coupe. Passenger space was little changed, although there was more headroom than the coupe could offer.

Combining Aston Martin's traditional virtues of style and performance with the joys of open-air motoring, the DB4 convertible is highly prized today.

The sellers at Bonhams note that this particular DB4 has flown under the radar for decades, never having been listed in the Aston Martin Owners Club Register. Even better, DB4C/1104R has had only two documented owners.

The current owner purchased the car in 1978 from its original owner, agronomist Geoffrey Emett Blackman. Blackman was the Sibthorpian Professor of Rural Economy at Oxford University and director of the Agricultural Research Council Unit of Experimental Agronomy there. His 1970 St. John's College parking pass, reading "Authority to park in the President's drive," is still affixed to the windscreen.

The original engine (no. 370/1134) had been replaced during Blackman's ownership (by the factory, it is believed). In 1980, the current owner removed the replacement unit (no. 370/472) with the intention of rebuilding it.

The DB4 was last MOT'd in 1979 (certificate on file) and has been laid up in dry storage ever since. The odometer reads a mere 60,000 miles.

The engine is now back in the car, which is presented in "barn find" condition, ripe for sympathetic restoration. The purchaser will also receive the instruction manual, workshop manual, parts catalog, and Swansea V5 registration document.

Pre-auction estimates for this rare Aston Martin DB4 convertible range from £80,000 to £140,000. With a recent DB4 convertible selling for £285,600, there's clearly an upside potential to bringing this car back to life. Its restoration promises to be an exciting and potentially rewarding project for any avid Aston Martin enthusiast.

Bonhams' Aston Martin Sale is scheduled for Saturday 21 May 2011 at the Aston Martin Works Service center, birthplace of the DB4 convertible in Newport Pagnell. For complete details, visit Bonhams online.