I saw a few in the 1937 to 1939 period
By: Mark in Paris : April 10th, 2017-08:44
You can have a look at these references: In 1937: in some 499, not all versions, even the 533 Chronograph (chronographs don't have often a swiss mention at all) In 1938: in some 560, 565, 598, 556, the 591 Chronograph, 1420 In 1939: some 1435 Maybe the pi...