Jose,

If you are having trouble identifying the movement, you can try looking at the Movement ID page on vintagewatchesonline. There are images of the Valjoux calibre's 71 & 72 and information about differentiating the two. Pay particular attention to the shape of the operating lever. Generally, a Valjoux 71 can be identified by the pointed end of the chronograph bridge. However, Heuer used a signature bridge on their Valjoux 71 that is shaped identically to the bridge they used on their Valjoux 72.

Michael