Romaric André, now widely known in the watch world as seconde/seconde/, went to the 2019 Baselworld trade fair to sell his first customized vintage watches. But while others exhibited their luxury wares in plush booths designed to dazzle, Mr. André spent his time opening and closing the lid of a cardboard box.

“It looked weird,” Mr. André, 43, conceded in a recent video interview from his home in northern France. But having spent 10 years in the industry as the co-founder of Celsius, a company that married a luxury flip phone with a tourbillon watch (the horological mechanism, which improves timekeeping accuracy, was visible in the phone’s lid), “some people knew I could be serious,” he said.

Among the drawings and actual dials he had inside the box was a timepiece he titled Solo Flight — a vintage Zenith chronograph that he said had been issued to the Yugoslav Air Force in the 1950s. The connection inspired images of old-school metallic planes and, in turn, a vision of rusting spacecraft from the “Star Wars” films, said Mr. André, who replaced the Zenith’s seconds hand with a tiny Millennium Falcon shooting a laser.

By the show’s close, the watch had caught the attention of two industry heavyweights: Carson Chan, then the Fondation de la Haute Horlogerie’s head of mission for Greater China, and William Rohr, best known in the watch world as William Massena, the founder of Massena LAB. Mr. André had his first two orders.

In the five years since, Mr. André has collaborated with several Swiss houses, including H. Moser & Cie, Louis Erard and, last month, Frederique Constant — an independent brand drawn by Mr. André’s “fresh and disruptive energy,” said the company’s chief executive, Niels Eggerding.