The answer is Shelby, whose teams of Cobra roadsters and more aerodynamic Cobra Daytona Coupés knocked Ferrari off its European perch during the 1965 season, with a string of wins at Monza, Oulton Park and the Nürburgring, plus a second at Spa - and, just for good measure, victory in Austria's Rossfeld hillclimb.
Winning the Championship, said Carroll Shelby, was "the most satisfying thing I ever did."
A boyhood dream come true
And one of the most satisfying things I have ever done - automobile-wise, at any rate - was to finally get myself into the cockpit of a 427 competition Cobra, a car I have been longing to experience since boyhood but which has somehow eluded me.
And the realisation of my dream couldn't have been much better because, not only was it organised by Las Vegas-based Shelby American at the fabulous Spring Mountain Raceway, it also happened in the company of drivers such as Bob Bondurant and Allen Grant, who helped the team to that auspicious World Championship win 50 years ago. Was I dreaming?
Admittedly, I only got as far as the passenger seat of the mighty, race-prepared snake... but what an experience, to be hurled around the circuit by someone who battled it out in these cars in period, and knows just how far you can go with 700 horsepower in a 900 kilogramme car before the rear end swaps places with the front. I now know what all the fuss about competition Cobras is for. And it's justified.
The second coming
The only drawback to such a Cobra baptism, however, is that I've now been affected by the venom and want to own one. Original '60s cars with race history are beyond the means of most, but Shelby American has marked this year's half century since the creation of the big-block, 427ci Cobra with a limited run of 50 CSX4000 anniversary specials with 23-gallon fuel tanks, leather trim, racing brakes and knock-off alloy wheels in the original, '60s design. And there's a choice of glassfibre bodywork in Guardsman Blue metallic with Wimbledon White racing stripes (from $119,995) or, if you really want to dazzle, highly polished aluminium (from $179,995).
After that, it's down to the buyer to choose his or her own engine/transmission set-up which, in order to be as authentic as possible, should comprise an iron block, 427-cubic inch engine mated to a four-speed manual gearbox - although there are plenty of other (less terrifying) options available.
If, however, you merely want to show your allegiance to the mightiest Cobra without actually having to buy one, luxury watch brand Baume & Mercier will sell you one of its more affordable, just-launched Capeland Cobra limited-edition chronographs, following the announcement of a long-term partnership with Shelby American.
World Champion in watch form
The entry-level model - which costs a reasonable £3,000 - features a 44mm steel case and is limited to 1,965 pieces (based on the Championship-winning year). Cobra-inspired styling cues include a clever 'snake's head' counter-weight on the chronograph second hand; a dial in Shelby's signature 'Guardsman Blue' with very subtle racing stripes; chronograph counters based on the car's instrument panel and a sapphire crystal case-back engraved with both a facsimile of Carroll Shelby's signature and an edition number.
For £13,300, meanwhile, you can have a version of the watch with a red gold case and a flyback chronograph movement, which is limited to just 98 pieces in recognition of Carroll Shelby's famous racing number.
And the good news is that they probably won't represent the last collaboration between Baume & Mercier and Shelby American because, according to the word on the street, we Europeans are soon going to be hearing a lot more about the legendary American hot-rod house that now focuses on tuning modern-day Fords - not least because the hugely popular Mustang (which Shelby Performance specialises in souping-up) is this year officially available in Europe.
Mustang chronograph, anyone?