Originally Posted by
southpawboston
Upon searching images of Jeunet mixtes, it's becoming clear that some models DID come with an all-chrome fork, so the fork may actually be original, unlike as I first thought.
After an exhaustive bout of Google Image searching by year (i.e.
1972 Jeunet, then
1973 Jeunet, etc.), it appears that the solid chrome forks were unique to the 1974 model year. In lieu of any other evidence, that may well be as best of a guess as I'm going to be able to get as to the precise age of the bike.