What happens when MR PORTER, a legendary Swiss watchmaker and a watch customiser put their heads together? .

“The idea came totally unwittingly,” says Mr George Bamford. “There was this book that used to sit on my desk – Manfred Rössler’s ‘bible’ on Zenith. When I first started talking with Zenith’s designers about a MR PORTER limited-edition watch, I immediately knew I wanted a minutes track around the dial’s circumference in a pyramid pattern.

“It took ages before I realised the idea had come subliminally – from the watch featured on the book’s front cover. It was too late to backtrack by then, plus, I was too in love with the look. So it was like, ‘Oh, OK, so we’re doing a heritage piece.’”

And so that’s what they did. But to call the Zenith X Bamford Watch Department Chronomaster El Primero Solar Blue Limited Edition a “heritage piece” is to ignore something: that this timepiece has nostalgic details but is still undeniably contemporary. No mean feat for something that not only distils the crucial elements of a stopwatch chronograph, but does so with one of watchmaking’s finest-ever chronographs – the first self-winding one to come on to the market back in 1969, and the first-ever to beat at the high frequency of 5Hz, which allows for a timing precision down to tenths of a second, rather than the usual eighths.

The Solar Blue is limited to 25 pieces, available exclusively to MR PORTER. The watch also has particular poignancy for Mr Bamford himself – a man whose eponymous horological customisation shop has grown exponentially in just a couple of years.

Mr Bamford’s interest in watches began when he was given a Rolex Daytona, another legendary chronograph, for his 21st birthday While it was a gift most people would give their right arm for, Mr Bamford over time realised that it looked, well, exactly the same as every other Rolex Daytona around the dinner table. What it needed, he reckoned, was the personal touch. And, in 2004, he went to the family business to find it.

“I have an obsession with black – black cars, black shoes, black everything – so I went to the R&D department at JCB, and they said there was this mining application: an anti-friction, anti-lubrication coating for drills called diamond-like-carbon or DLC. You get a rock-hard, bluey-black finish like nothing else. So we coated those two Rolexes.

“Then, that summer, we got 25 orders for this.”

Spying a business opportunity, Mr Bamford turned permanently from yellow diggers to black watches, forming his eponymous Watch Department. BWD became the watch world’s coolest tuner – a sort of unauthorised but equally adept Mercedes-AMG for top-end Rolexes, Officine Panerais and Patek Philippes.

Then, last year, Mr Bamford was contacted by Mr Jean-Claude Biver – who revived Blancpain in the 1980s and proved that the mechanical watch still had a place in a quartz world. Mr Biver is famed for his ability to turn around watch businesses, working his magic at Omega in the 1990s, then dramatically at Hublot, the subsequent purchase of which by LVMH placed him at the top of the luxury group’s tree.

“Jean-Claude visited about two years ago,” Mr Bamford recalls, “And simply said: ‘Why are you working on watches by companies who don’t want to work with you? Come and work with me!’”

Mr Biver retired in September this year, but his last great, disruptive act was authorising BWD and its clients to customise Zenith, TAG Heuer and Bulgari watches through the BWD website. Not only was it a triumph of long-overdue validation for Mr Bamford (his proprietary, UK-developed “military-grade titanium” coating is revolutionary in the industry) but it also paves the way for personalisation in a sector that has traditionally been resistant to it.

BWD has now developed a slick new customiser app that affords near-limitless permutations of colours, details, straps, markings, engravings. Its instant acceptance might have something to do with Mr Bamford’s near limitless enthusiasm, not to mention a devoted client base. In fact, so devoted, that they inundated Mr Bamford with requests for a purchasable version of BWD’s “service watch”, which has now led to its very own timepiece, the Mayfair; a £425 quartz beauty, also available through MR PORTER.

With the Solar Blue, however, Mr Bamford more or less became the client himself, making use of Zenith’s own custom shop. “In keeping with the nostalgic vibe drawn from the ref 3818 on the cover of Rössler’s book,” he says, “I wanted a retro, faded blue for the dial. But the boys in Zenith’s lab said they had this new ‘solar blue’ – and once I saw it first-hand, there was no contest. Pictures can do it no justice.”

He’s right – as well as its almost ethereal shimmer and shine, the gradation radiates from light to dark, where most “flare” dials fade the reverse way. It’s a hypnotic look, especially suited to the clean, uncluttered design of the El Primero chronograph’s purest iteration.

“Heritage 146 is just such a cool take on the El Primero,” Mr Bamford enthuses, “but it still isn’t the one people first go for. And that slightly bugged me. I wanted to do the Heritage 146 justice, but – and bearing in mind it’s so economical in design – just a little bit different.”

And so, all the unique details: there’s a red-accent on the running-seconds subdial, taken from a 1950s chrono by Zenith; the pyramidal minutes track, sourced from the aforementioned ref A3818 from 1971; a historically correct 38mm case, but with a clear caseback revealing that legendary movement. “It’s important to pay homage, but why do an exact copy of an original?” he says. “If I wanted that watch, I’d just want to buy that original. As a fan of Zenith, I just wanted to create the thing I wish they had done.

“Being afforded the opportunity thanks to Zenith and MR PORTER”, he adds, “Well, I’m like a kid in a candy store!”

The Zenith BWD Chronomaster El Primero Solar Blue is available in a limited edition of 25 pieces, each individually numbered. Read more about it here.