I'd have to search a bit, but I don't think compulsory proof in France was established until 1960/1962. In 1923 France had new proof rules to mimic the 1914 International Proof Conference rules but law wasn't implemented until mid 1926. Not sure what went on between 1926 & 1960. Reciprocity w/ France may not have been established/occurred until early 1960s.

Kind Regards,

Raimey
rse