According to this movies's Wikipedia page, this movie sold 2,186,603 tickets in France. I looked up the general ticket price around that time period, also using Wikipedia. If we should believe the numbers that are situated in the table, we can assume that in in 1957 the price was 1.33 F (or $0.37) and in 1965 3.04 F (or $0.62). I've decided to focus on the USD amount because that's what tmdb uses as revenue input.

Now as you've noticed there are no numbers from 1964, so i had to interpolate. The difference is $0.25 and 8 years. So (0.25/8)x7, the times seven to get the amount for the appropriate year, and it equals about $0.59. Well, 2,186,603 x $0.59 results in $1,290,095.77 USD.

Of course these numbers are probably far from accurate because most of the calculation is based on hypothetical numbers (also I'm bad at math). But I believe this could be an estimate of the revenue this film made.

Signing off, A teenager with too much time on her hands