Even now, a quarter of a century on, the defining images quickly tumble back. One is Keith Houchen launching himself through the air to score one of the more spectacular goals Wembley has ever seen. Another is the Spurs defender Gary Mabbutt with his head in his hands, taking in the enormity of his own goal (pretty cruel, by the way, that Coventry's supporters named a fanzine after the responsible knee). Later, there is the sight of Brian Kilcline, all sweat and wild hair, taking the FA Cup from the Duchess of Kent, gritting his teeth and thrusting it to the skies. "Killer" went on to renovate houses in Holmfirth, the (fictional) home of Nora Batty, and grew his beard down to his belt, ZZ Top-style.

The heroes from 16 May 1987 are commemorated now in the Sky Blues Wall of Fame stretching down one side of the stadium, just off junction 3 of the M6, where the club now do business. An impressive ground it is, too, if you like that sort of thing. Considering what has happened since Coventry signed the tenancy agreement, though, one suspects most supporters would prefer the tattiness of Highfield Road if they could go back in time to the days when everything seemed so much more innocent.

The nostalgic qualities from that sun-drenched afternoon at Wembley can certainly make you pine for the days when the FA Cup was in its pomp. Coventry's players will wear a specially designed 1987-style kit – striped shirt, navy shorts and sky-blue socks – when the teams renew acquaintances at White Hart Lane on Saturday. John Motson remembers it as the best final he has commentated on in 40 years in the business. Talk to John Sillett, one half of the victorious managerial duo with George Curtis, and the first thing he says is: "It was the greatest day of my life."

As for the fans, they tend to cling to the memories like some form of comfort blanket, and who can blame them? Supporters always hark back to the past when there is precious little worth celebrating in the present and for Coventry it has been a dismal run of managerial changes, relegations, boardroom coups, broken promises and serial disappointments since we saw Sillett and his Wembley sunburn, jigging and galumphing on the pitch, drunk on euphoria and pretending to swig champagne from the trophy. "Our proud peacock", as Cyrille Regis later described him.

Sillett is a life-president at Coventry these days and still organises a get-together for the players who won the club's first and only major trophy. "Twice a year. We're a very close team. We all join up, in a pub of choice, and reminisce about the good times."

But it has been bleak for Coventry, to say the least, since that 34-year run in English football's top division, avoiding relegation on the final day of the season 10 times, ended in 2001, the misery encapsulated in that photograph of a middle-aged man with tears streaming down his face, holding up a sign that read: "We'll be Back."

The man in question, a home-and-away stalwart by the name of John Mullaney, later wrote a book with that title. But Coventry never did come back and Mullaney, like his team, went down under, moving to Australia. The team are currently 11th in League One, having dropped as low as second from bottom before the appointment of Mark Robins. Their average crowd is barely 11,000 and the two-thirds-empty Ricoh Arena is turning out to be the noose around their neck.

That is the backdrop to this tie: a long, complex dispute with the stadium owner, ACL, about the amount of rent that is feasible when the club are essentially skint and labouring in the third tier. As it stands, the annual charge is £1.3m and they have reluctantly explored the possibility of moving, possibly to Kettering, to a ground "where we can afford to play". Before Christmas, they were threatened with a winding-up order unless they stump up the £1.1m they owe.

"We moved to a stadium where we didn't own a single seat or blade of grass," Sillett says, almost despairingly. "We don't get a penny from the restaurants, the bars, the casino. All we get is the gate money. What kind of deal is that?"

It has, he says, been "very painful" to watch the decline. "Coventry, the city, has been through some difficult times, with factories closing and people losing their jobs. The city needs a successful football club. It would be a disgrace if we had to leave the city and we have to make sure it doesn't happen."

Everything was certainly a lot different back in 1987 when "George and John" – to quote Coventry's cup-final song Go for it – decided to prepare for the biggest match of their lives by taking the players for a three-night stopover in Bournemouth, incorporating golf, a trip to Oxfam for a dodgy T-shirt competition and, finally, some old-fashioned boozing. Sillett had a mate who ran a pub in the New Forest. "We would get there for 1pm," Regis remembers, "and he would close the pub for us." Even the night before the final, at the team hotel in Marlow, the players stayed up in a way that would scarcely be imaginable now. "We went into town and bought some beer from the off-licence, went back to the hotel and chilled," Regis says.

There was, to use Houchen's phrase, plenty of "let's-hope-we-don't-lose-eight-nil humour". Tottenham were a pretty formidable side back then, in their third final in seven years. They were looking for a record eighth victory, had never lost a final and had Glenn Hoddle, Ossie Ardíles and a host of other internationals. Coventry? "We were misfits who had been recruited from all sorts of clubs, usually at a time when things weren't going well for us," Regis, now a football agent, puts it. "Tottenham had players who could have torn us apart if they hit their peak."

Clive Allen, the most formidable scorer in the country, put them into the lead after only two minutes. Houchen remembers walking back for the restart fearing the worst. "When we talked about it afterwards one or two of the lads admitted thinking: 'We're not going to get battered here, are we?'"

What happened next, starting with Dave Bennett's equaliser and culminating in a 3-2 victory for the underdog, was so momentous – Mabbutt, incidentally, has the good humour to recognise himself as an "absolute legend in parts of the Midlands" – the restored bells of the bombed cathedral rang out for the first time when the open-top bus carrying Coventry's players inched its way through the city the next day. "It was supposed to take half an hour," Sillett remembers. "We were still on it three hours later. That's how many people turned up." The Coventry Evening Telegraph at the time observed: "It would be difficult to overestimate the effect of this match on the spirits of our city."

"Schnoz", as he was affectionately known, is often credited with his team‑talk before extra time, with the score at 2-2. "It was 80 degrees, a boiling hot day, and we were all sitting around," the winger Nick Pickering says. "Sillett looked round and said: 'Get on your feet, just look how tired they are.' We looked over at the Spurs players and they were shattered."

Sillett, though, still thinks the real masterstroke was to get permission to train at Wembley the day before the game. "I rang the groundsman and he said: 'No way, we can't do that, I haven't done that in 25 years working here.' But we wangled it. They even played piped crowd noises to get us used to the atmosphere. And we had a pretend trophy with a walk up the steps to collect it. We wanted to protect the players so none of them would be surprised on the day. And it worked a treat."

Can they undo Spurs again? The difference this time is that there are 52 places separating the two sides in the order of English football, rather than it being 10th versus third in the old First Division as it was back in 1987. Sillett, however, thinks it can be done. "Remember, I suffered the worst day of my football life in the FA Cup when Sutton United beat us in 1989. If they could do that to us, we've got to have the belief we can do it to Spurs."