Hi Don,
The weight is definitely right and the description of the certificate seems to match. Also, the certificate is genuine: I have seen others from the same period and yours match these. However, I am puzzled too by the certificate number (I had never noticed this before). Would it be that it has nothing to do with the edition number but with the number of certificates issued that year.
It is only a thought, I am no specialist of modern French weights.
SophieB