A rare 1950s Mercedes-Benz has sold at a US auction for over $9.3million (£7.2m) at the weekend… but it’s far from ready to be showcased at a classic car show anytime soon.

The 1956 Mercedes 300SL ‘Alloy’ Gullwing is one of just 29 lightweight aluminium-bodies examples of the German marque’s most famous sports cars. However, this one hasn’t had the cherished life it arguably deserved.

Instead, it has been crashed into with a forklift truck, stripped of its parts and left to the elements in a barn for decades by its previous owner.

The dilapidated fifties classic was sold at the weekend in Los Angeles alongside around 70 vehicles found in a ‘lost collection’, many of them in a similar – if not worse – state of disrepair having been unearthed from the ‘greatest barnfind ever’. 

RM Sotheby’s ‘The Junkyard’ sale was hosted in the US on Saturday, though some of the 550 lots are lots still available as part of an extended online auction.

Everything available to the highest bidder has been collated from The Rudi Klein Collection, which includes a bounty of rare cars, motorcycles, trucks and an abundance of spare parts.

Since 1967, Klein, a renowned figure in the world of collecting, quietly amassed a remarkable collection of automotive treasures that he retained in a modest junkyard in Southern Los Angeles. 

Known for his discerning eye and passion for rare and unique vehicles, Klein’s collection has long been a well-kept secret, with only rumours of its existence swirling amongst certain collectors’ circles.

The weekend marked the first opportunity for collectors to acquire significant models from the haul – many of them long thought lost or destroyed.

And the 300SL Gullwing Mercedes was the standout lot of them all.

Its sale figure significantly eclipsed the pre-auction estimate of $6million (£4.6m) as collectors were not deterred by its neglected condition. 

In fact, the $9,355,000 paid was only just shy of the $9.5million world record price ever paid for a 300SL Alloy Gullwing, which was achieved in 2022 – and that example was in significantly better shape.

Codenamed ‘W198’, the 300SL coupe is commonly referred to as the ‘Gullwing’ due to its upward-opening roof-hinged doors. Coupe versions were produced between 1954 and 1957 and a cabriolet offered until 1963.

However, bosses in 1955 decided that a small run of Leichtmetallausführung (meaning light metal version) ‘competition’ examples should be made for well-heeled amateur racers, with this car being number 26 of only 29 produced over a 12-month period of which few survive today.

These super-rare ‘Alloy’ models not only featured a lightweight body but were also equipped with a more powerful 3.0-litre NSL in-line six-cylinder engine, sports suspension, Rudge knock-off wheels, and Plexiglas rear window and side screens.

While the standard 300SL cost around $7,000 (£5,400) when new, Alloy variants had a significant $1,307 (approx £1,000) mark up.

Completed on 12 January 1956, chassis number 198.043.5500872 is significant in that it was the sole example of these rarefied cars finished in Schwarz Black paint with contrasting red leather interior. However, it has since been painted silver.

It was delivered new to Luigi Chinetti, a former winner of the legendary 24 Hours of Le Mans as a racing driver and – at the time – Ferrari’s North American importer and owner of the famous North American Racing Team (NART). 

It is believed that Chinetti commissioned his Alloy Gullwing purely to compare the Mercedes-Benz to his then-current Ferrari stock.

Chinetti and Klein met during the 1976 Daytona 500, where the pair agreed the sale of the Alloy Gullwing for $30,000 (around £23,000) and the German sports car was collected a year later.

Receipts and photographs supplied in the history file show the ‘sound with no damage’ condition of the Gullwing when it was acquired by Klein – though that’s no longer the case today.

Rudi tucked the car away inside the central building of the junkyard, where it remained for the following 47 years before being unearthed by the auction house.

Parts were stripped and sold over the five-decade stretch, including the front bumpers, gear knob, tool kit and jack, and the spare wheel, though the rest is completely original.

While many of its sister Alloy models were wrecked in racing excursions, Klein’s stripped-down example is believed to have survived largely unscathed, bar a small collision in 1981 when the collector accidentally backed a forklift into it, causing a prominent dent in the rear that remains today. 

Its odometer shows the car as covering 73,387 kilometres (45,600 miles) at the time it was catalogued, with RM Sotheby’s stating describing the Mercedes as ‘unimpeachably, spectacularly genuine’.

‘Junkyard’ Lamborghinis and other rare classics also sold for big sums

The Mercedes 300SL Gullwing Alloy wasn’t the only ultra-rare motor in the Klein collection to be left to fall into a state of disrepair over decades of storage at his LA premises.

A similarly-stripped 1957 300SL Roadster also sold to the highest bidder for $1,187,500 (£950,000), while a 1935 Mercedes 500K ‘Caracciola’ Special Coupe by Sindelfingen – a one-off car built for legendary champion racing driver Rudi Caracciola –  was the second priciest sale at the weekend, making an incredible $4.1million (£3.2m).

Also sold from the outstanding junkyard collection were three Lamborghini Miuras – the model often considered the world’s first ‘supercar’.

The most expensive of the trio was a 1968 P400 by Bertone – the 159th of 275 examples built and stored by Klein for 46 years – which changed hands for $1,325,000 (£1m).

A dust-covered earlier 1967 example – the 53rd Miura built – fetched $610,000 (£470k) while a later 1969 model made an eye-watering $967,500 (£745k) despite missing many components, including its clamshell bonnet.

Including the motors already mentioned, seven cars from the Klein Collection were snapped up for prices in excess of $1million.

Speaking to This is Money about the sale, a spokesperson for RM Sotheby’s said: ‘The Junkyard has undoubtedly gripped the entire collecting car fraternity, with both its rarity and condition of the examples on offer. 

‘We were delighted to see some of the astonishing results when the cars crossed the block, in particular the 1956 300SL ’Alloy’ Gullwing, which was one of just 29 built and was the only Alloy ever to be delivered in black, which achieved a remarkable $9,355,000. 

‘It was a true once in a lifetime sale and some of the figures were truly astounding.’