Before the 1993 Méhaignerie Law, I'm not sure how this would work.
France never had a pure ius soli. Being born to foreign parents, you would only be French from if your parents were themselves born in France. Otherwise, you could become French, at your majority, under various conditions. The details have changed somewhat but those changes are not relevant here, leaving at the age of four would not give you any automatic claim to French citizenship.
This would require to speak with a French lawyer. Normally laws in France are not retroactive: if your case dates from before a law was passed (like, in your case, the Méhaignerie law of 1993), the previous law applies. So, logically, you'd fall under the 1945 law (modified in 1973, but that wouldn't apply to you). Where it says that you're French from your birth if you're born in France with at least one French parent, and from the time you become an adult (21 back then) if both parents are foreigners.
So that was the law then. Only a lawyer will really know whether you can use this, or whether the Loi Méhaignerie applies to everybody, regardless of the year of birth. My bet is on the changes applying only to births after the law was passed, but IANAL...