Dr No[Moderator Omega - Wristscan]
37606
The first-ever automatic chronometers . . .
. . . would be my suggestion.
Omega references 2499 (33 mm) and 2500 (35 mm) released in 1948 to commemorate their hundredth anniversary with unique chronometer-grade movements; both were limited editions issued mainly in yellow gold with a smattering of rose gold versions. Dials, hands, and even springbars are 18 kt gold.
Art