2007 April 20.
The hand-setting:

After completing the loop shaped spring, after finding its elasticity, it is to shorten, see arrow.

What's to be done:
(20) The small spring, formed like the origin and set in the original bore hole. It is not a screw but a conical pin which fits tightly in the bore hole. The screw slot helps to turn the part when readjusting a tension to its end to push against the lever.
(21) The brass lever was missing. It locks the loop shaped spring position (or unlocks) if the castle wheel for hand-setting has to mesh with the setting wheel.
(22) The setting wheel has the wrong diameter. It is to manufacture.