A cobwebbed window in a ramshackle store located in a nondescript Buenos Aires suburb. Adidas expert Gary Aspden animatedly recounts the moment a friend emailed him this photograph. “The shop window was stacked floor to ceiling with old blue Adidas boxes. Stuff from the ’78 Argentina World Cup and before. I started having palpitations.”

His cardiac arrhythmia is understandable: the photograph was a treasure map. Since trainers became a collectable commodity in the 1990s, finding rare original styles has become harder and harder. Independent sports stores in Europe have long been cleaned out by vigilant trainerphiles for whom dead stock (styles no longer in production) equals vintage gold. Original Adidas are particularly hard to find, as the brand has resonated across underground and popular culture for decades, sought by everyone from old-school Bronx rappers to catwalk models. Not to mention the music gods of Manchester.

Aspden knew he was getting on a plane immediately with fellow collectors and Adidas collaborators Mike Chetcuti and Robert Brooks, but when friend and former Stone Roses frontman Ian Brown heard about the bounty, he declared he was coming too.

Facebook Twitter Pinterest Ian Brown of the Stone Roses – a massive ‘sneakerhead’ – smiles in front of the undisturbed stock Neil Bedford Photograph: Neil Bedford

They knew there might be trouble ahead. “We were told the shop owner was a little… moody,” Aspden says, alluding to 75-year-old Carlos Ruiz, a local legend who is, by all accounts, unpredictable. He sits in his sportswear shop every day but not in order to sell anything. One Ruiz tale concerns the director of a big budget Maradona movie who wanted to use the store as a location – when he pulled out a chequebook, Carlos threw him out. Getting into Aladdin’s cave was not going to be easy.

Facebook Twitter Pinterest The closed front of Carlos Ruiz’s Aladdin’s cave Neil Bedford Photograph: Neil Bedford

With this in mind, the group didn’t mention they had a British rock star among them (“We didn’t want to rattle Carlos”). But it was Brown, who speaks a little Spanish, who unearthed the tragic facts behind Ruiz’s eccentric facade. A decade earlier, two youths had shot and robbed Ruiz in the shop. It took him two years to walk again. Widowed and returning to work, he discovered the licence had changed hands, meaning all stockists needed to reapply for an account. “They sent a lot of forms to fill in,” he told Brown. “I’m 65, I’ve lost my wife, I can barely walk.” He ripped the forms up.

Bobby Gillespie wears SPZL half-zip knit, £205 Photograph: Kevin Cummins

Since that tragic homecoming, Ruiz has kept hold of his old shoes, describing them as “a noble product”. He sits in the shop every day, amid the dust and cobwebs and columns of old stock, an obscure duty he sees as therapeutic. Aspden’s assessment is more literary: “He’s the Miss Havisham of the sportswear world.”

Unexpectedly he let them in, giving them two days with his priceless cache. Wading through the haphazard boxes in 45C heat, the pilgrims found treasure after treasure: 30-year-old Handballs, untouched Silver Winds. Some of the polyurethane soles crumbled to ash upon contact, adding to their grail-like aura. Ruiz even let them buy a few pairs.

The 1970s rarities sourced from Ruiz’s time capsule led to a new collection: the premium Adidas Spezials – 12 pieces of clothing, four pairs of shoes. It’s not a straight vintage reissue, but simply draws on Adidas’s own history. Aspden challenged himself to recreate an Adidas aesthetic without relying on the signature three stripes. The classic Beckenbauer track jacket is reimagined in luxury wool, with lined pockets. The Touring shoe has cup soles, as seen on Adidas Trimm Trabs. Quintessential contours are adhered to, branding reduced to pin badges and undercollar tape.

Facebook Twitter Pinterest Soles of shoes which have perished over time Photograph: Neil Bedford

The sneakerheads who stumbled across a South American time warp guarded by a suspicious gatekeeper is a hell of a story. But isn’t it somewhat self-mythologising for Adidas to turn to Adidas for inspiration?

“Bowie’s last album sleeve was Heroes reappropriated. The last James Bond film has him driving around in an Aston Martin,” Aspden muses. “If everybody else is referencing you, why not reference yourself? There are so many classics in the catalogue that I’m playing with the crown jewels of design.”