The retro uniform was a recreation of that worn by the team at their first Formula One world championship race, the 1954 French Grand Prix at Reims, won in a Mercedes by Juan-Manuel Fangio.
All the support team and hospitality staff also dressed in vintage clothing as they recreated a 1950s atmosphere on a welcome cooler morning after overnight rainstorms swept away the record-breaking heat of previous days.
The team's cars are running this weekend in a retro livery with a predominately white front end, reflecting the original German national racing colours before Mercedes became the 'Silver Arrows'.
While Mercedes is celebrating the past, it is being cautious about the immediate future. On Friday, team boss Toto Wolff said Mercedes will delay a decision on their 2020 driver line-up until the break in the calendar after next week's Hungarian Grand Prix.
That announcement piled the pressure on Valtteri Bottas who is the only realistic rival to defending five-time champion Lewis Hamilton in this year's title race. The Finn trails him by 39 points at the midway point of the season.