Many thanks for your response. But although it looks as if it is part #31 I can find no way to get it or the spring to do anything useful if its in the postion shown.
I enclose a photo with the red arrow pointing to the setting lever that needs to be pushed in the direction of the arrow when the shutter is cocked. I still cannot see how this is done by the lever and spring. I really need a photo of this part of a Vario shutter but so far I have not found anything on line.