Hello Marc,
Your vase is the model Fontenay, indeed a design from Graffart, registered as CG479 and it's illustrated in the 1947 catalogue. I'm not sure how long it was in production for but they made a lot of them, and it doesn't appear in the 50's anymore, in my opinion the blue ones, especially petrol-bleu, and Chinese green are the nicest.
The most complete book for Graffart designs is the reedition of the catalogues 1951-1975, its cover is orange and you can buy a new one for €40 on Ebay.
Hope this helps....