Omega Official website reference to this watch

http://www.omegawatches.com/collection/speedmaster/date/35132000

Rare Olympic Edition Automatic Speedmaster. Omega Los Angeles 1932.

This Particular watch reference is the first in a series of four chronographs commemorating milestone achievements. For the first time ever all olympic events were officially timed to within 1/10th of a second using the Omega Chronograph.

This watch reference 3513.20 should not be confused with the reissue 3516.20 where the olympic rings were added as counter weights to the centre sweep hand.