Don't know about pulling the prop through! Does it get that cold in France?
One thing I have learned is that if the POH says 'Six pumps on the primer for a cold start' don't just pull it out and plunge away. You have to wait for the thing to fill up. Our 28 is a sod for that, it takes ages for the primer to get going, you can feel the extra pressure when you try and prime. Once I sussed that then cold starts are a breeze.