Before we take a closer look at Erich Lexer’s 30 mm Chronometer, let’s have a look at its “protagonist”. Omega produced the 30 mm caliber from 1939 until 1963. The book deals with this movement’s chronometer-certified version, which had a relatively short lifespan. Omega made these calibers between 1941 and 1954 only. Development of the Calibre 30 began in 1938 following the designs of Mr. Henri Kneuss (assistant technical director at Omega). The finished product was presented in December 1938 and production began as early as February the next year… More here.
Looks like a decent read.