He discovered and reconstructed the Celtic harp of the Middle Ages, and, along with his harpist son Alan Stivell, was responsible for its revival in Brittany in the 1950s.
He was a winner in the Lépine competition for several artistic works: he made an "astignomètre" (an ophthalmological device), created a table lamp (sold by Lancel - French leatherwear), built furniture like a cabinetmaker (French polish and marquetry) and painted in an original technique "of water-color in oil" on panels of hardboard painted in white, which were shown at an exhibition of independent artists at the academy of Raymond Duncan.
On the eve of the Second World War Georges was fifty years old, and although he was over the age limit for his rank (captain of the reserves) and not ably fit, he considered it his duty to answer the call and was allocated to the east army to Épinal and to Saint-Dié.
Fanny was working in the secretarial department of the civic and social Feminine Union, at 25 Rue de Valois.
He tried to recreate the Celtic harp, an instrument forgotten when the Duchy of Brittany lost its independence, at the end of the Middle Ages.
He did research about it in the years 1946-1951, increasing his number of meetings and document retrievals, until finally he produced a prototype based on his personal designs.
At the age of sixty three, he brought ambition, passion and perfectionism to this work which began in April 1952 and lasted a year.
Fifteen years of work allowed him to create a "perfect and magical harp" according to his son, realizing his dream in the early 1950s.
In 1964, he created an instrument inspired by the 15th or 16th century Irish harp, fitted with metallic strings which gave him a tone similar to the twelve-stringed guitar or zither.