Duesenberg chassis 2506, powered by supercharged engine J‑488, is one of the rarest and most distinctive late-production Duesenbergs. Fitted with elegant Convertible Sedan coachwork by Derham of Rosemont, Pennsylvania, it combines the performance of the legendary SJ with a body style that successfully balances luxury, practicality, and sporting character.

Chassis 2506 is especially significant because it is one of only five Convertible Sedans bodied by Derham. The design is attributed to the celebrated stylist Gordon Buehrig, whose influence helped shape some of the most elegant automobiles of the 1930s.

Unlike more formal closed-body Duesenbergs, the Derham Convertible Sedan offered a more sporting appearance while retaining generous passenger accommodation. The body's clean lines, balanced proportions, and low profile make it one of the most attractive open four-door designs ever mounted on a Duesenberg chassis.

Beneath the coachwork lies one of the most formidable powerplants of the era. Engine J‑488 is a factory-supercharged version of Duesenberg's famous 420-cubic-inch dual overhead camshaft straight-eight.

A particularly notable feature of chassis 2506 is its dramatic one-piece external exhaust manifold, one of the defining visual characteristics of the supercharged SJ models. Sweeping elegantly along the side of the hood, it instantly identifies the car as one of Duesenberg's most powerful creations.

Unlike many concours-winning Duesenbergs that have undergone multiple restorations, chassis 2506 has benefited from remarkably careful long-term ownership. For nearly forty years, it has remained in the collection of Tom and Susan Armstrong.

During this period, the car has never undergone a complete frame-off restoration. Instead, it has been sympathetically maintained and refreshed as necessary, preserving much of its authenticity and character while ensuring continued functionality and presentation.

This philosophy of preservation has allowed the car to retain a sense of continuity that is increasingly rare among the world's most significant Classic Era automobiles.

As one of only five examples of its type and a remarkably well-preserved survivor, chassis 2506 remains a compelling reminder of why the SJ is still regarded as one of the greatest luxury performance automobiles ever built.