A. Monge has a small mechanical workshop preparing cars for the competition. R. Rowe is an electricity specialist (head of the research department of Fulmen) with a gift to draw automobile bodies. These two friends have already worked together during the war to make small electric Fulmen vehicles. From 1949, they were led to join again their efforts. A. Monge wanted to enter a car of his design based on Dyna in the Le Mans. He asked R. Rowe for the study of the bodywork. Thus was born the Callista that Raymond Gaillard and Pierre Chancel piloted at the 24 Hours in 1950. Monge and Rowe did not have sufficient capital to manufacture this convertible, they appealed to Raymond Gaillard who became a financial partner of the brand and distributed the Callista convertible, renamed in the meantime, Coupe des Alpes, after its good results in the race of the same name.
For the Salon de Paris in 1950, R. Gaillard also asked Callista to prepare a sportier roadster called "Ranelagh", named after the street where his Panhard garage is located.
Callista Ranelagh roadster and Coupé-des-Alpes cabriolet were presented at the 1950 Salon de Paris by Raymond Gaillard of the Grand Garage Molière, at 64, rue de Ranelagh, Paris. With its 610cc Panhard engine it completed the 28th in the 1950 Le Mans 24 Hour race, co-driven by Gaillard.