THE APOGEE OF ROADSTER PRODUCTION

When Mercedes-Benz introduced the 300 SL Roadster in 1957, the new model addressed many of the perceived shortcomings of the outgoing 300 SL Gullwing. Primarily, a redesign of the Gullwing’s tube frame allowed for the use of conventional doors, which improved the ease of ingress and egress. This refinement also allowed for the implementation of standard wind-up windows, significantly improving cabin comfort.

The unforgiving high-pivot swing-axle geometry of the Gullwing coupe was discarded in favor of a low-pivot swing-axle rear suspension. This configuration utilized a coil spring mounted transversely above the differential that was linked to the axles by vertical struts, serving to minimize oversteer. The frame and suspension redesign also facilitated the installation of softer coil springs, which provided the Roadsters with a more comfortable ride quality without compromising handling. The highly developed inline-six-cylinder engine was standard-equipped with the sport camshaft that had been so effective in the racing alloy-bodied coupes, increasing horsepower by 25.

In 1961 four-wheel disc brakes became standard equipment, improving the 300 SL’s stopping capabilities, thereby bringing the model in line with concurrent mechanical advancements at Ferrari. A year later, the engines were updated with aluminum alloy blocks, helping to minimize weight. Just 210 Roadsters were reportedly factory-equipped with disc brakes and alloy engine blocks, making these cars the apogee of 300 SL development—and a rarity in the bargain.

AMONG THE FINAL: CHASSIS 003188

An accompanying copy of its factory data card illustrates that this 300 SL Roadster—the 139th of those final 210 examples—is a US-market car which was delivered new on 5 August 1963 and clad in White Gray (DB 158) over a red leather interior (1079) with black soft top and matching White-Gray hardtop. Additional specifications furnished to this order included a Becker Mexico radio, sealed-beam headlamps, whitewall tires, and instrumentation in miles with standard 3.89 ratio rear axle. Though its early ownership history is unknown, by the late 1990s the car had been imported to the Netherlands.

RETURN TO DEUTSCHLAND

In April 2005, this 300 SL was acquired by a German dealer of specialty automobiles on behalf of a noted Mercedes-Benz collector and former rally driver from Berlin. Photos on file show that sometime immediately prior to its exportation from the Netherlands, it had been recently treated to a complete restoration and finished in the period-correct color of Medium Red (516) over a black leather interior and matching soft top. This theory is further supported by the fact that its new owner immediately completed a trouble-free edition of the famous 2,000-kilometer German “Oldtimer” Rally with it.

After several years of spirited enjoyment, in early 2010 our subject lot was then consigned back to the importing dealer and, from there, acquired by the renowned marque specialists at Kienle Autotechnik in Heimerdingen for their sales inventory. Upon receipt, it was decided that the car did not fully meet the firm’s exacting standards for presentation or accuracy, and as such this 300 SL Roadster was offered for sale with the condition that it was to undergo a complete and total restoration to original specifications executed by their staff. If anything, this made the sales proposition for this very late alloy-block roadster exceedingly more desirable to potential buyers, and the car was quickly snatched up by a repeat Kienle client from Oestrich-Winkel, Germany.

WITH LOVE FROM KIENLE

Images and nearly €430,000 (~$475,000) of work orders on file from Klaus Kienle thoroughly document the following six years of its transformative restoration to the stunning concours state in which it remains today. Beginning with a complete disassembly of the 300 SL’s famous tubular construction and steel body, absolutely no cosmetic or mechanical detail escaped redress during this endeavor. While the structural condition of the chassis was verified and its shapely body corrected to a sufficient degree, every mechanical component, underpinning, and assembly was exhaustively rebuilt with OEM parts or replaced as needed.

Inspection of the car’s major drivetrain components reveals its alloy-block engine and 3.89 rear axle are numbers-matching units compared to those listed on the its factory data card. Its four-speed synchromesh gearbox, stamped with number 003511, was apparently installed at a later date, but is of the correct type. The only noteworthy stylistic changes to this 300 SL’s original form appear to be a tan soft top, and 3.89 metric speedometer.

Additional equipment specified by the client included Kienle’s bespoke fuel injection pump system, engine modifications for the use of modern unleaded fuel, floor mats, and a rear trunk clothed in red leather with two pieces of matching luggage. A light smattering of more modern conveniences such as a battery kill switch, improved firewall insulation, hazard lights, 12-volt socket, and an improved diaphragm spring for the clutch were also furnished at the previous owner’s request.

Now presented today in its original color combination of White Gray (DB 158) over red leather with a matching hard top, this 300 SL Roadster is absolutely stunning. The consignor reports that between his ownership and previous, the car has traveled fewer than 300 kilometers (~185 miles) since completion of its restoration.

Among the most desirable modern Mercedes-Benzes is the Roadster, and many consider that the one to have is an alloy-block, disc-brake car. Having been completely restored by the “German pope” of world-class 300 SL specialists, this particular chassis would be a fine acquisition for any enthusiast looking to experience the sensory pleasure that the comes with driving this famous model on the open road.