Cal. 13 is a column wheel monopusher chronograph produced by Landeron in the 1940s.
Dr. Ranfft suggests that it is “like 11, but stronger main spring”. Given that Cal. 11 has a six column wheel, it is likely that it is a two-pusher unlike Cal. 13. Images of this movement and Heuer watches that used it support the notion that it is a two-pusher movement.