Here's a link to a better diagram showing how the stop is supposed to work.
http://www.velo-pages.com/main.php?g...serialNumber=2
The stop, Ref. 2694, hits the notch on the lever, Ref. 2948, on the right side. The left side is similar with stop, Ref. 2695, stopping lever, Ref. 2949. They are designed to work with both the clip or the braze-on, Ref 599.