Down the years, Smith has received many offers to dig the dirt but prefers to focus on being, "part of the revolution of English football, now the biggest entertainment on the planet. It also deals with my cock-ups, of which there have been many."
One not in the book is the request from a sportswear company to advise on a youth footballer to be the focal point of a major campaign. The options were England schoolboys captain Tommy Caton and promising young midfielder David Beckham.
"I looked at both and said: 'Go with Tommy Caton'." He has never lived it down.
Cock-ups notwithstanding, he has been an innovator within his field through the First Artist company, having overcome personal tragedy and disability. His mother died from lung cancer when he was 15; his first wife, Lee, died from leukaemia four years after they married.
As a child, he was afflicted by a crippling stammer. "I promised Mum, in halting English, that I would make her proud. I had some success in my own small way as a junior athlete [he represented England as a sprinter]. We were very close. She was my translator."
Smith was cured of his stammer at 17 after a scarily extreme "tough love" therapy course, which would doubtless be outlawed today. It also provided him with life skills and mannerisms which have proved invaluable during tense negotiations.
For example, "look at the bridge of the nose of the person you are talking to, use pauses and never blink", he says giving a convincing demonstration. He is a patron of the British Stammering Association and lists "early testing to help cure 90 per cent of the world's stammerers" as his remaining ambition.
His first business venture was a music company named MEI in the unrealised hope that people would confuse it with EMI. A subsequent venture fared better, being in the vanguard of the Northern Soul boom. Two days after Lee's death in 1981, he sold up and was a millionaire.
"I was 29, financially good and personally miserable," he recalls. "I spent my 30th birthday in LA on my own. I saw the world from the bottom of a whisky bottle for two years. I don't drink whisky any more. My liver has absorbed a lifetime's supply."
His road to redemption stemmed from seeing a TV news item about a film business called First Artists. "I just liked the name and thought: 'I am going to do something with it'." A burgeoning interest in American sport and entertainment led the Arsenal fan to suggest a management business to Gunners and England striker Paul Mariner. "The idea was to make our players rock stars like they were in the US."
The business started at the top by winning the England football team account. "In those days, agents sold stories about players to papers. I said: 'I'll give you all the info for free. Just don't cut the brand names out of the photos."
With sponsors such as Coca-Cola and Mars on board, the players were encouraged to play ball, particularly in friendly games. Smith says that at the end of his pre-match briefing, the then England coach Bobby Robson would say: "Jon wants a word. We've got Coca-Cola involved in the game. When you score, run to their advertising board."
A fond memory is of Paul Gascoigne looking around frantically after scoring before racing to the half-way line and throwing himself to the ground close to the requisite signage.
Fortune played a huge part in Smith representing the most talented and controversial player of the era, Diego Maradona. Traffic problems had twice prevented the agent taking up an invitation to visit the home of Maradona's fellow Argentine Ossie Ardiles. He made it on the third occasion and was taken aback when Ardiles broke off from a phone call with the player to ask: "How do you fancy working for Maradona?"
"The best player I've ever seen," Smith enthuses. "He was at Napoli and if he didn't fancy going for training, it would be put back two hours." Maradona had a collection of top-of-the-range cars and, when the agent queried the point in a city of twisting roads and frequent traffic signals, the player replied that the rule of stopping for red lights did not apply to him.
Smith once rang a friend who ran an Italian restaurant in Brookmans Park in Hertfordshire to book a table for 32.
"Don't be silly it's Saturday night," he was told. "But one of them is Maradona…" Unsurprisingly, the booking was accepted and when the party, also including Gary Lineker, arrived "a tear ran down the owner's face. It was one of those lovely moments."
The company's deal with England ran until the mid-90s, by which time the Premier League was under way. Sky hired him as a consultant in the early days of coverage and he now concedes that the pre-match fireworks and dancing girls were probably an Americanism too far.
First Artist clients Peter Beardsley, Tony Cottee and Gary Pallister were all involved in Britsh transfer record deals. International cricket and rugby teams joined the roster and Smith also owned the London Monarchs American football team.
The company branched out into travel, hospitality, a theatre business and financial services.
But First Artist had borrowed heavily to expand and the football agency world had changed with the implementation of transfer windows, shoehorning much of a year's business into a few months. Although in an era where "debt was still a good word", the company at one point owed the banks £23 million and was days from going bust when it was purchased by American entertainment group Pivot in 2011.
Smith and younger brother Phil - who had long been involved - bought back the name and some of the football dealing and the business is now known as First Artist Mission, following a merger with a company co-fronted by cricketer Kevin Pietersen.
He was in Rio for the Olympics as chair of British Taekwondo - "I like the idea of taking aggression off the streets" - and was delighted by the team's three-medal haul.
He had previously been co-opted on to the Remain team for the EU referendum with the brief of winning over the sporting community. Although some football clubs were supportive, they were scared of going public for fear of alienating fans backing Brexit.
The Southgate Progressive Synagogue member visits Israel regularly and he and his second wife Janine have a home in Spain. Sons Ross and Scott are a chip off the old block with respective roles in digital marketing and celebrity management.
Outside of the sporting arena, one of Smith's proudest assignments was a UK speaking tour for former Soviet leader Mikhail Gorbachev in 1993. Smith says that discussing the Middle East peace process over dinner one night, Gorbachev recalled summoning Yasir Arafat and Hafez al-Assad to Moscow to tell them "you have to start talking to Israel".
His best deal? Although it was heavily his brother's doing, "taking Kevin Phillips to Sunderland when he was at Watford going nowhere - and potentially to Basildon. He became one of the biggest heroes Wearside has ever had. At his final game, the Stadium of Light crowd gave him the largest ovation I've ever heard at football. You can't buy that."
High among the toughest negotiators is Spurs chairman Daniel Levy, who got the Smiths to take a box at White Hart Lane, figuring he could make back some of their commission. "Bearing in mind that we are Arsenal fans, my brother asked: 'Can we have a box that doesn't face the pitch?'
"Daniel is very difficult to negotiate with and does it with an engaging smile, which makes it even harder. You know you've lost a thumb or finger. You think you'll get it back on the next deal but you never do."
In the book, Smith writes that only a tiny fraction of the 1,600 UK agents make the kind of money that annoys people. To those easily upset, he counters: "Don't be influenced by a big number. If you are trading commodities in the City and making huge commissions, no one minds. But they seem to object to football agents being paid a few million pounds when they've made someone millions of pounds."
But isn't the cash-swamped Premier League a licence to get rich quick for anyone with a few connections?
"Big players want big services, so the bigger agencies are benefiting," he reasons. "The smaller guys are left trawling around reading the Sun to find deals where they know somebody and try and grab a little piece of them."
His sales pitch to a prospective client? "I will surround you with everything because I don't want to lose you - accountancy, lawyers, lifestyle. If you want a Porsche I'll get you a cheaper Porsche than anyone else. If you want to be on the red carpet for the next Bond film, I'll get you there. They are the Hollywood stars of our generation."
He smiles again, focusing unblinkingly on the bridge of my nose.
