Mercedes-Benz returned to prominence on the international stage at the Frankfurt Auto Show in April of 1951, showing an all-new top-of-the-line luxury car: the W186 Model 300. Production began in November that year, lasting through three different series until 1962. Built in both four-door saloon and cabriolet versions, the 300 combined updated, though classic-inspired, styling with modern technology highlighted by an all-new 3.0-liter overhead-camshaft six-cylinder engine, independent four-wheel suspension, an electric dash-operated adjustable torsion bar suspension, and pedal-operated centralized lubricating system.

Referred to as the 300 b, the second series began production during the 1954 model year. Upgrading to twin dual-barrel downdraft Solex carburetors and increasing engine compression to 7.4:1 boosted horsepower by 10, and vacuum-assisted power brakes and front door vent windows were also added. In total, 146 300 b Cabriolet Ds were built, with only 59 examples built in 1955.

This Mercedes-Benz 300 b Cabriolet D holds the unique distinction of being the “Standwagen” Factory show car dispatched for exhibition at the 1955 Toronto National Motor Show according to the data card supplied by Mercedes-Benz. The model is often called the “Adenauer”—a name earned because the 300 series was instantly favored by Konrad Adenauer, the first chancellor of the Federal Republic of Germany, for chauffer-driven use. However, few examples of the 300—this car among them—can actually claim a direct connection to Adenauer himself. For decades, chassis number 00359 has been called the “Adenauer Mercedes” because it was reportedly used by the German Consulate in New York City. As the story goes, this 300 b Cabriolet D chauffeured Audenauer on his trips to the United States when visiting New York and surrounding areas during the mid-1950s.

Correspondence from the second owner, also includes a classified advertisement published in the New York Times in 1964. It was then that this Mercedes-Benz was sold to its third and present lady owner, who has lovingly cared for this Cabriolet D the past 57 years!

Maintained in largely original condition throughout, the original interior and convertible top are untouched on this 300 b. Over 50 percent of the paint is believed to be original, with newer paint applied to the front end and finished to a high standard so that is nearly undetectable without close examination. The car has been serviced by noted restorer Jim Capaldi for the past 30 years with invoices documenting work; most recently, the fuel tank was restored, an electric fuel pump added, and carburetors rebuilt so that it runs and drives as it should.

The car is equipped with a full factory tool kit, complete set of original fitted luggage, top boot, jack assembly, and emergency parts kit. A Data Card accompanies the car, along with a modest file of receipts and correspondence (including an amusing letter from the second owner to his mechanic complaining about a $92 tune up in 1963), plus title history dating back decades.

An unrepeatable opportunity awaits the next owner, who will find a well-preserved and nicely accessorized original Mercedes 300 offered out of 57-year current ownership—one that drives as only a low-mileage, top-of-the-line Mercedes-Benz can.