The ORGA number

Citroën uses a system that allows to calculate the production date of the car. The so-called ORGA-number was stamped on the firewall right above the ID tag. This number was incremented every day by 1. This makes it easy to evaluate the production date.

If your 2CV still has its ORGA number visible, you can convert this number into your car's birthday.
Just find the ORGA number on the photo and click on it.