Tommy Milton drove his Miller 122 to victory in the 1923 Indianapolis 500, which was the first time this legendary race was considered part of the International Grand Prix series. The watch also nods to the Cunningham racing stripe which was not introduced by American, Briggs Swift Cunningham II until much later in 1951 at Le Mans, as the first ever racing stripe. U.S. Cars raced in white and the team introduced the blue stripe to distinguish their team from other U.S. Teams.
It is highly appropriate that it is sported by the C70US as the famous blue parallel lines on white ground have become synonymous with American motor racing.
The car I have paired the watch to is the Cunningham C2R from the 1951 Le Mans race, the first to sport the Cunningham stripe.