“MG” stands for Morris Garages, which was the Oxford distributor for Morris cars; co-incidentally, it was also owned by William Morris, later Lord Nuffield. When Cecil Kimber became its general manager in 1922, the firm started modifying standard Morris Cowleys, lowering the chassis and fitting more sporting bodywork.

By 1924, Morris Garages was advertising the “MG Special four-seater Sports”, and incorporated the famous octagonal badge into the copy. Old Number One was the first MG sports car, but it was the 48th body built for Morris Garages by one firm, Carbodies, since 1924.

Morris Garages outgrew its home three times before moving to Abingdon in 1929, by which time it had been renamed the MG Car Company. During the early 1930s, MG became synonymous with the term “sports car”, and its road cars were promoted by successful racing forays. Then, for fiscal reasons, Morris sold his private companies, including MG, to Morris Motors in 1935.

Purists argue that MG was never the same again. There was less variety in the products, racing activities were limited, and placing the MG badge on BMC saloons such as the Morris Oxford and 1300 would have been anathema to Kimber. Realists would point out that even after Kimber’s death in 1945, fine, affordable sports cars such as the TC, MG A, Midget and MG B continued to be built, and it was only British Leyland’s appalling management that sullied a great name in the 1970s.

Car production was stopped at Abingdon in 1980. From 1982 to 1990, the MG name was applied to re-badged and tuned Maestros, Montegos, and Metros, but MG enthusiasts were cheered by 1992’s RV8 and have more to celebrate with the introduction of the mid-engine MG F, which draws heavily on the corporate parts bin. Back to the beginning, really.

Nice one, Cecil

This is the first MG sports car: it has skinny tires, no power and hopeless brakes – but is it still a great car? There was only one way for Mark Gillies to find out.

It is not every day that you drive something which is so much a part of a car maker’s history that it is effectively priceless – but that is what I am doing at the wheel of Old Number One, the first sports car ever to wear the MG badge. Auctioneers and MG experts shy away from giving it a definitive value – with what could it be compared? – but we would be talking about 250,000 if it ever came to auction.

But let us put value out of our minds, because that is not what this spindly 70-year-old sports car is about. Instead it speaks eloquently of what MGs have always been built on: speed and fun. Despite being an assemblage of Morris components, Old Number One has a verve that belies its humble underpinnings.

It was sprightly in its day, having a top speed of around 70mph when the most flamboyant of sports cars could barely top 100mph. Today, it feels slower than the most stately of shopping cars. Yet it is fun to drive, because MG’s founder Cecil Kimber knew about the basics of a good sports car.

For a start, its skimpy bodywork gives it a racy appeal. Its major controls respond well, with the steering and throttle pedals having particularly pleasing actions. And it makes a lovely throaty rasp under acceleration and a staccato backfire when you lift off the throttle. Built by Kimber or hill climb trials, the MG is a joy to throw around, its anorexic Dunlop Cord tires able to cope with the (lack of) power in the dry, but sliding delightfully on wet and muddy roads.

You feel a part of this machine. You hear every component in action, feel the blast of icy air over the scuttle, and even pop gently out of your seat in sympathy with the car when it skips over bumps. Where in modern cars you are insulated from the machinery, here you have to be attuned to it. The clutch cannot be slipped and the gearlever cannot be hurried, otherwise the cogs grate in protest: you need to let the engine revs die while changing up and speed them up while downshifting to effect quiet changes.

The brake pedal acts only on the front wheels, while the outside lever actuates the rear brakes. Stabbing the pedal has about as much effect as trying to blow a house down, so in emergencies you also reach for the outside lever. You cannot say that it is comfortable, either. There is no weather protection not even a windscreen. The only source of warmth is the heat of the engine wafting back into the cockpit, so it pays to wrap up.

While modern-car drivers would find Old Number One lacking in creature comforts, they would also be confused by the dials and controls. In the 1920s, a good driver was constantly alert to the machine, so this car has attractive silver-faced Smiths dials to monitor fuel and oil pressure, engine revs, road speed and the condition of the electrical system. The water temperature gauge is a glorified thermometer (“The Boyce Motometer”) set on the radiator cap.

Other controls in the cabin include a fuel pressure pump, a lever for ignition advance and retard, and a fuel mixture dial, vital for starting in cold weather. Ah yes, starting. This is a bit of a palaver.

If MGs are all about having fun, then that fun started here, 70 years ago.

Flick on the ignition and fuel pump (now a modern electric device, added for convenience), retard the ignition, check that the gearlever is in neutral – it would be embarrassing to run yourself over as you stand by the prow in cranking position – open the bonnet, flood the carburettor by pulling its top, turn the starting handle and hope that the engine fires. All of this would have been standard procedure in 1925 when Kimber helped to bring the MG (Morris Garages) name to the public’s attention with a faultless performance in the Land’s End Trial, a premier sporting event. Organised by the Motor Cycling Club, this test of performance and durability started in Slough and finished at Land’s End.

Kimber produced this car specially for the event: although Morris Garages built several cars before 1925, FC 7900 or Old Number One is regarded by Rover and the British Motor Industry Heritage Trust as the first MG sports car. It had a bespoke chassis frame into which was fitted an overhead valve Hotchkiss 1.5-litre four-cylinder engine giving about 38bhp. Morris axles and brakes were used, special springs made, and racy Hartford friction dampers fitted at the rear. Carbodies of Coventry built the two-seater bodywork, which has sketchy mudguards and hopeless lighting: two small lamps mounted above the twin spare wheels and a single glow-worm at the back.

After Kimber had finished with it, he sold it to a friend in Lancashire. It returned to MG in the early 1930s after allegedly being found on a scrapheap in Manchester, and has been in the care of MG’s owners ever since. In that it proved Kimber’s genius for taking unlikely components from the parts bin and then assembling them into lively, good looking sports cars, it is the beginning of the MG legend. If MGs are all about having fun, then that fun started here, 70 years ago.

Originally published in the Electronic Telegraph. The Electronic Telegraph is a Registered Service Mark of The Telegraph plc.