Input (grade 12): The first Derny 'Entraineur' or 'Bordeaux-Paris' models, with their characteristic petrol tank across the handlebars, were built by Roger Derny et Fils of the avenue de St Mandé, Paris, France in 1938.
Output (grade 2): The first Dernys were built by "Roger Derny et Fils" of Paris, France in 1938.