Come late 1965, the arrival of the new DB6 left Aston Martin with a surplus of DB5 chassis built to a shorter wheelbase.

Rather than simply putting those spares to one side, the Newport Pagnell factory conceived an “interim” convertible that combined the sporting proportions of the outgoing car with the latest styling flourishes adorning the DB6, including split bumpers and special chrome finishers for the taillights.

They retained Touring’s patented Superleggera construction technique, which wrapped handcrafted alloy panels around a lattice of small-diameter steel tubing to create light but rigid coachwork.

Just 37 of these so-called DB Short-Chassis cars would be built to make it the rarest-ever series production Aston Martin droptop.

New lettering on the boot lid also signified the marque’s first use of the “Volante”—Italian for “flying”—nomenclature that remains a fixture six decades later.

The early example offered here is believed to have been delivered new to North America,...