This crystal radio originates from France, but I acquired it at an antique shop in Estella near Pamplona (Spain) during a short visit to a local radio collector in July 2001 (thanks Javier and Maria-Theresa for your hospitality !).
The schematic is quite straightforward. The antenna is coupled to the top of a LC parallel circuit. The capacitor is fixed (about 400 pF) and the inductor consists out of two series coils with taps. One coil is for PO ("Petites ondes"), whereas the other is for GO ("Grand ondes"). The crystal is connected with one side to the top of the antenna circuit and the other side to a filter capacitor (about 1700 pF) and the plus of the headphones (2x 500 ohm). (See schematic)
Very probably this crystal radio is a Dyna radio, model Kiddy. It is depicted in "Le Grand Livre de la TSF" by Jean-Michel Bourque (page 65).