Fellbach, Germany - In March 1952 Mercedes-Benz held a media conference in the middle of nowhere, on the autobahn between Stuttgart and Heilbron - and stunned the world's motoring journalists as the prototype W194 came howling past at 230km/h.
It was a low, streamlined sports-racing car with a three-litre, straight-six engine in a space-frame chassis with doors that opened upwards like the wings of a seagull.
It was the first purpose-built racing car from Mercedes-Benz since the Second World War and, under the model name 300 SL, the gull-winged coupés went on to take second and fourth in that year's Mille Miglia, a 1-2-3 clean sweep at the Bern Sports-Car Grand Prix (this was when motorsport was still legal in Switzerland) first and second in the 24 Hours of Le Mans, first, second, third and fourth in the Great Jubilee Prize at the Nurburgring, and first and second at the Carrera Panamericana in Mexico.
The first two prototypes were created entirely by hand in Rudolf Uhlenhaut's Stuttgart-Untertürkheim racing workshop; the following eight, which were the ones that were actually raced, were built in a batch at the Sindelfingen factory, using pressed body panels so their shells, at least, were identical.
There was one significant change, however; the prototypes had very short doors, more like aircraft hatches, which made entry and exit awkward and laborious. So the eight “team” cars had their gullwing doors extended down into the side sponsons of the body, giving the car an unmistakable profile with the doors open.
The very first 300 SL was used as a test mule at Untertürkheim; it had a very hard life and has long since been scrapped. The second one, by contrast, is not only still complete, it has never been crashed or raced in anger, although it was on hand as the team's spare car at Bern and did some laps in practice.
So when the Mercedes-Benz Classic Centre in Fellbach was tasked to restore a 300 SL for the celebration of the model's 60th anniversary in 2012, there was no question which was to be the chosen car: chassis no. 194 010 00002/52 - the only one in existence with the original short doors.
And there is no doubt this is the original car - it has the number “2” stamped on every major component.
The brief was to restore the car exactly to as-built 1952 specification while retaining, as far as possible, the patina imparted by 60 years of driving.
First the car was completely stripped and the tubular space frame carefully measured; thanks to this car never having been crashed it was within the tolerances specified on the original drawings.
Restoring the body was a lot more difficult, however. It's made of very thin (significantly thinner than the “team” cars') aluminium/magnesium alloy sheet metal and it's very, very delicate. Time has left its mark in many places, including the scars of earlier partial restoration efforts.
It took five months to restore the body to its original condition, taking care not to polish out the original hand-welded seams or to make it “too perfect”. All the panels were hand-formed and even when it was new it wasn't quite symmetrical - so that's how it is now.
Painting the body created its own, unexpected problems; in 1952 all the 300 SLs were finished with a semi-gloss nitro-cellulose lacquer in the factory's official racing colour, called “silver bronze”.
To recreate that paint would have been relatively straightforward, but nitro-cellulose paints are now illegal due to environmental concerns and it took exhaustive research by the original paint supplier, based on contemporary colour photographs and films, to produce a near-perfect colour match in a water-based paint.
In the all-out quest to add lightness, none of the original windows (not even the windscreen) was glass; they were all made of aircraft-grade plexiglass, which after 60 years, was more translucent than transparent. Incredibly, the windscreen, the side windows with their air flaps and the rear window were provided by the same supplier who made the plastic glazing for this 300 SL in 1952.
The W194's engine was derived from that of the Mercedes-Benz 300 (W186) sedan, and the block of this SL has the number “186” embossed on it, while the modified cylinder head, on the other hand, bears the number “194”.
At the time, Uhlenhaut's race-shop technicians boosted its output to about 125kW with hotter cams and three Solex sports carburettors. The engine was also converted to dry-sump lubrication and tilted 50 degrees to the left so it would fit under that rakish bonnet.
Only just: there's about a centimetre between the hand-fabricated air-filter housing and the underside of the bonnet.
The original engine was stripped down and overhauled; when it was finished, the technicians ran it for 10 hours on a test rig, including a brief burst at full throttle, which delivered a textbook 125kW!
Their biggest problem was reconditioning the dual electric fuel pumps, for which no spare parts exist; every component they needed had to be painstakingly re-created by hand.
But then most of this car was hand-made in the first place, including the exhaust system, the fuel tank, the windscreen washer fluid reservoir and the seat frames.
And everything was made as light as possible; the seat frames are aluminium, the transmission bell-housing, the rear axle and the steering box are made of magnesium.
What made this restoration possible was that the car was virtually complete; The big, hand-carved three-pointed star on the radiator was polished up and went straight back on, as did the original 300 SL lettering. The original rear number plate “W59-4029” was still there, although the front number plate was missing and had to be copied from old photographs.
The wood-rimmed steering wheel, the gearshift knob, instruments and switchgear were all present and correct. The seat covers were re-created using the same distinctive blue tartan pattern, while the roof lining and the rest of the fabric trim were cleaned and replaced.
The restoration team was surprised to find that the original front axle was not only drilled full of holes to lighten it, but also nickel-plated - until an old hand pointed out that it made potentially dangerous hairline cracks instantly visible to the pit crew.
The rear axle, in particular, showed that this car had never been thrashed; all the differential gears were in virtually new condition.
The original Alfin brake drums were tested, skimmed and reinstalled; the riveted rims were shod with Dunlop D8 tyres.
It took nine months to restore the oldest Gullwing in existence but it was worth it; this is clearly not a shiny new replica but a beautifully cared for, absolutely priceless, 60-year-old motoring icon in perfect running condition - a fitting tribute to one of the most successful racing cars of the 1950s.