©2021 Courtesy of RM Sotheby’s
For the buyers who were in the market for a convertible in the early 1970s, there was no finer choice in the world than the 280SE 3.5 cabriolet. It was the fastest, most lavish, and most expensive convertible offered by Mercedes-Benz, arguably the finest automobile manufacturer in the world at the time, making this a very special automobile indeed. This 1970 Mercedes-Benz 280SE 3.5 cabriolet is finished in silver with a blue convertible top. It rides on chrome knockoff wire wheels wrapped in Continental tires. The interior is trimmed in blue leather, accented by a wood dash and trim. It features a Behr air-conditioning unit, dash clock, Blaupunkt AM/FM radio with cassette, and a wood-rimmed Nardi steering wheel.

SCM Analysis


Vehicle:1970 Mercedes-Benz 280SE 3.5 Cabriolet
Years Produced:1970–71
Number Produced:1,232 (claimed, possibly more)
SCM Valuation:$297,000
Tune Up Cost:$800, including valve adjustment
Chassis Number Location: Inside right front structural rail
Engine Number Location:Left side of bellhousing behind cylinder head
Club Info:Mercedes-Benz Club of America
Alternatives:1972–73 Ferrari 365 GTS/4, 1971–95 Rolls-Royce Corniche, 1980–89 DeTomaso Longchamp Spyder
Investment Grade:B

This car, Lot 157, sold for $198,000, including buyer’s premium, at RM Sotheby’s Hershey auction on October 7, 2021.

This is the least-expensive functional and genuine 280SE 3.5 cabriolet we have seen sold at auction in recent years. Because its chassis number starts with 111027, we know it is the real deal.

A glance at the auction catalog fails to disclose a critical issue: This car was born in color code 350H, Mercedes Blue, instead of silver. I will never call a color change on a Benz “well executed,” but it was hard to tell that this was a color-changed car. And while we are picking it apart, let’s get some of the other obvious issues out of the way. The Nardi wheel, wood shifter and the wire wheels do not do the car any favors, nor does the chrome fender trim. As it is a Canadian car, underside photos would help a lot in determining what lurks beneath the surface. However, if this 3.5 cabriolet checks out, it could be a great deal. I can’t help but fantasize…

A $75k question

I imagine myself the purchaser of this 280SE 3.5. What really needs to be done to it? How could I make it into a great example? If I can keep to a budget of $75k, I could still have an upside when I’m done. I have a few ideas.

I would need to start with mechanicals. Most W111s need subframe and rear-axle mounts. While inside the rear axle, I would remove its original 3.69 ring-and-pinion, install a new 3.27 ring gear and recalibrate the speedometer. This would make the car nicer to drive at highway speeds. Parts for this job would be about $6,500 and labor about $7,000. This would include all the rear axle bushings and bearings, as well as front subframe rubber, tie rods and a steering coupler.

Under the hood, I would replace all the fuel hoses with new parts from Mercedes, thus avoiding a fire. I would also replace any worn breather hoses, belts and coolant hoses. A new timing chain might be needed as well, and to top it off, I would build a set of look-alike Mercedes plug wires with genuine parts. I would not do a full engine-bay detail, however. Wanting this to be a great driver, I would rather allocate my resources adjusting valves and fine-tuning the injection system than making it look brand new. Let’s say I would spend another $5,000 or so under the hood.

Dialing in the details

To deal with the less-than-glamorous touches, I would source a correct steering wheel and chrome shift lever. An ivory wheel would be nice, but I’ll take whatever I can get. I would also pull the awful chrome wheel eyebrows. I don’t know why anyone would install these. They reek of poor taste.

While I would normally prefer wheel covers, a set of 6.5-by-14 Bundt alloy wheels will look nice with my eventual paint job, and then I won’t have to worry about the typical steel-wheel vibrations (or painting the hubcaps). A set of Vredestein Sprint Classics (size 205/70VR14) would be a great tire choice.

Because I live in Florida, I would have to have great air conditioning. I would source a New Old Stock compressor on eBay or reseal the original, replace the a/c drier and charge the system with R12. All of this might set me back another $3,000.

Back to Mercedes Blue

I am assuming that this car does not have any major rust or RM Sotheby’s would not have accepted it. In case it does, I would allocate about $15,000 to rectify any hidden rust or structural issues. With my rust-repair budget, I would be flexible, as this is likely the most important area. Following any rust repairs, I would remove the chrome, windshield and other exterior parts and have the car stripped and repainted in its original 350H Mercedes Blue. This is a great color — eye-catching, unique and mysterious.

I would allocate about $30k for paint and the amelioration of any unforeseen body issues. This would also leave a $10k emergency margin to deal with any other strange problems, such as broken glass, transport charges, etc. It would also leave me some extra money to buy new door seals and window seals, or to fix any leftover details. As an aside, I wouldn’t touch the interior. There is nothing I detest more than the sterility of new leather.

A market-beating proposition?

Once the car is finished and reassembled, roughly one year later, I would spend about a thousand miles shaking it down and testing it. This 3.5 cabriolet says a lot about today’s collector-car market. Many buyers blow off the imperfect cars with some needs, only to find out that they have purchased a cosmetically solid car that needs mechanical sorting. Yet for around $275k, our subject car could be a reliable, cosmetically refreshed 280SE 3.5 cab with most of its mechanical issues fixed. This would be a market-beating proposition, as many of these cars start at $250k–$290k.

If our subject car is a rust-free example and there are no ugly structural issues lurking beneath the surface, I would call this well-bought, with a lot of room for improvement. I hope the new owner has a healthy imagination and a few extra dollars to spend. ♦

(Introductory description courtesy of RM Sotheby’s.)

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