Originally Posted by
clubman
Why would you think the Cyclo gears were added later? Many bikes of the period had them. It even has a braze on for the spring.
If you take another look at the close up of the Cyclo lever you can see an original braze-on for a different lever just beside it.
It wasn't just Cyclo using these springs and the Huret that i have fitted uses the same spring.
Also on the frame and chain stay there are two braze-ons for running a single cable to the rear derailleur.