The first part to be fitted is the blocking lever spring which keeps the blocking lever (brake) against the centre seconds chronograph runner when the chrono is off. It fits close to the click spring in this aperture.
And then the hammer stem bolt and spring in this cut out.
And both fitted.
And then the actuator cams at the lower – this is a cam operated chronograph as opposed to the pillar (column) wheel chronograph system.
The spring for the lower cam which controls the coupling clutch is fitted.
Then the operating lever yoke and spring.
And then the operating lever.
The next stage is to fit the chronograph runners for the second and minute chrono hands and that continues here.