The fact that the late George Daniels was regarded by many as the greatest watchmaker of the 20th century – and by some as the greatest since Abraham-Louis Breguet – makes it a given that he should have had a magpie-like attitude to collecting interesting wrist and pocket watches. So it was no surprise that the dedicated Daniels auction organised by Sotheby's in 2012 a year after his death should be replete with an eclectic array of portable timepieces.

Among the lots in what proved to be an £8.2m sale were everything from a cylinder watch made in Augsburg, Germany as far back as 1550 to an inexpensive, quartz-powered 'talking watch' produced by Trafalgar in 1983. There were pieces, too, which had served as test mules during the great man's development of the Co-Axial movement, examples of modern makers whom he greatly admired – such as François-Paul Journe – and many watches by Omega, the brand that so benefited from Daniels' horological genius.

But that Sotheby's sale gave an insight not just into Daniels the watchmaker, but also into Daniels the collector of all things quality.

Elsewhere among the lots were some of the many clocks that graced the rooms of the Daniels homes on the Isle of Man and in Herefordshire, including ship's chronometers by Hamilton and Arnold, mantel clocks by Dent, Tompion and Breguet – and a fabulous longcase model by Englishmen Thomas Mudge and William Dutton.

'I remember that one in particular,' recalls his celebrated protege Roger Smith, 'because George told me how he had been riding past a shop on his motorbike when he saw this clock in a shop window. He stopped to ask how much it was, and the price was far more than he could afford – but because he thought it was too good to pass up, he sold lots of other stuff on the basis that he knew that this was probably the only chance he would have of owning a clock by Mudge and Dutton.'

Anyone who has had the good fortune to visit Smith's own Isle of Man workshop will know that it is equipped with the tools amassed and used by Daniels during his long career – among which is a small collection of antique watchmaking equipment which, says Smith, his mentor began acquiring during the late 1960s.

'He originally bought them not just to collect, but for practical use,' says Smith. 'He had got to know Professor David Torrens, Dean of the medical faculty at Dublin University and a noted scholar of horology. Professor Torrens had studied the type of tools that Breguet and his peers would have used, and George initially felt he needed the same sort of equipment in order to make his own watch – but then realised that was the wrong way to go and bought modern jig borers and lathes.'

Daniels would have had no regrets about his early purchases, however. He simply loved all things mechanical and dedicated his life to the study and practice of engineering in many of its different forms, not least as an avid enthusiast of veteran, vintage and classic cars and motorcycles.

When I worked at Sotheby's back in the 1990s, those of us who arrived by motorcycle were allowed to park on a narrow strip of pavement beside the Aeolian Hall, a satellite of the main building behind New Bond Street that was once a BBC recording studio.

One morning, having completed my 50-mile commute from rural Oxfordshire, I was kneeling on the ground struggling to relocate the cam chain tensioner bolt into my ancient Yamaha after it had rattled loose en route – at which point a man drew-up on a well-ridden BMW.

He stepped off the bike, assessed the situation and, taking the recalcitrant bolt gently in a giant hand, deftly relocated it before starting the engine and adjusting the previously clattering cam chain to silent perfection. It was my first encounter with George Daniels, who had also arrived for work that day in his capacity as a consultant to Sotheby's clock and watch department.

But only later did I discover that his fascination with micro-engineering extended to things held together with far larger nuts and bolts – vintage Bentleys. Daniels first car was a 1932 MG J2 which he bought in 1951, two hours before the crankshaft broke and, in his own words, 'set me on a career as an amateur motor mechanic.'

Just five years later, however, he was able to realise an ambition of Bentley ownership by buying a dishevelled 1924 three-litre with Gurney Nutting coachwork – for £100.

In his autobiography 'All in Good Time', Daniels noted that, after a decade as a practicing watch repairer, he had 'not one social companion in the trade'.

The Bentley however, brought him into contact with fellow enthusiasts of the marque, the circle of which grew extensively during what proved to be a single-handed restoration of the behemoth to pristine perfection that saw Daniels working 'four 16 hour days on the watches and the remainder of the week on the Bentley.' 

A more sporting, four-and-a-half-litre model followed, which provided Daniels with an entry to the Vintage Sports Car Club and the Bentley Driver's Club – and a chance to compete on a track that resulted in a meeting with VSCC founder member, Sam Clutton, the very man responsible for introducing Daniels to the world of antique watches (and Breguet in particular) that was to form the foundation of his subsequent, stellar future in horology.

Daniels remained a VSCC member for the rest of his life, buying, racing and selling ever rarer and more interesting old cars in the process of building what could only be described as a blue-chip collection that, when it crossed the block at Bonhams in 2012, realised almost £10m. 

The absolute star was the 1929 supercharged 'blower' Bentley in which Sir Tim Birkin set a Brooklands lap record of 137mph. It sold for more than £5m, while another Birkin car, a 1932 Alfa Romeo 8C-2300 that he had entered into the 1932 Le Mans 24-Hour race, achieved in excess of £2.5 million. 

The Daniels motor houses – which included a string of specially-constructed garages within a giant barn at his Herefordshire home – also contained his beloved 1954 Bentley R-Type Continental (owned by him for 26 years), the remarkable 1908 Grand Prix Itala 'Floretta' that previously belonged to Clutton and, for regular use on the Isle of Man (sometimes for fish and chip collecting), a 1974 Jaguar E-Type.

The car he most loved, however was a 1907 Daimler T-45 that had originally belonged to the fourth Earl of Craven.

'Allowing for its idiosyncratic behaviour and its occasional bouts of sulking and refusing to co-operate, it is my favourite car,' wrote Daniels in All In Good Time. 'The car I would keep if allowed only one. With its hissing carburettor, exposed valve gear and whirring chain-drive to the wheels it has all the uncomplicated charm of the primitive creation, the very essence of the horseless carriage. For that most enjoyable of all motoring experiences – just meandering through France with nothing to do more urgent than eating and drinking – it is the perfect carriage.'

Tania Brown, the secretary of the VSCC, was only 10 years old when she first marshalled at an event in 1990 – but she recalls Daniels as being 'a leading figure in the club for a very, very long time. He joined in 1959! His genius as an engineer meant that everyone was rather in awe of him and, with his enthusiasm for competition and really getting out and using his old cars, he epitomised what the club was all about.'

It was cars and motorcycles, too, that led to Daniels forming a 50-year friendship with David Newman, now the chairman of the trustees of the George Daniels Educational Trust. 

'I was a local authority surveyor in south London when George was living in Penge, where he established himself as a watchmaker,' Newman told A Collected Man. 'He came to me with a planning inquiry, we got talking about our mutual interest in cars and motorcycles and soon became firm friends.'

Daniels personal interest in two wheels saw him not only collecting motorcycles, but using them, too. And, as with everything, his natural eye for exceptional engineering came to the fore in recognising the most collectable models long before others cottoned-on – notably his two BMW R90S sports tourers and two MV Agusta 750 'Americas' which were, more or less, race machines registered for the road. 

Other bikes owned by Daniels over the years included a 1910 v-twin Matchless, a 1959 Norton International in 'clubman' race trim and two luxurious Sunbeam tourers, both of which were sold by Bonhams alongside the Daniels car collection – with one fetching a record £11,500. 

Newman recalls how the pair would travel all around the country together in search of long-case regulator clocks that Daniels would advertise for in the Antiquarian Horological Journal, and how the co-writing of the book 'Watches' with Clutton led Daniels into another collecting sphere – that of Leica cameras.

'He became interested in Leicas as a result of using one for the photography for the book – and he ended up collecting them.'

Daniels amassed no fewer than 27 Leicas which, as with the other collectable items from his estate, were auctioned-off to raise funds for the Trust – in this case, a relatively modest £15,000 or so.

'George simply understood and recognised quality and knew when something was worth buying,' concludes Newman.

'His house on the Isle of Man was what I would call a gentleman's residence. Plenty of well made, brown furniture, clocks in every room, good oil paintings on the walls – and several bronzes by the sculptor Eduardo Paolozzi, a close friend and a fellow car and watch lover. He made several bronzes of George and could often be found passing the time by tinkering in the watch making workshop.'

Thanks to the legendary Daniels eye, the Trust benefited from the sales of the Daniels collections by around £20 million, all of which is being used to support students of horology, medicine and construction.

There were things that Daniels didn't want to be sold, however, and those were the many trophies he had amassed from successful outings with the VSCC, Bentley Driver's Club and other motorsport organisations.

'George asked that those be dispersed among the friends who he had made through his love of cars – a thank you for giving him a lifetime's enjoyment,' says Newman.