I believe that this is a flyer handed out at a French trade show in 1949. Points of interest include:
As late as 1949 there is only one basic type of derailleur shown or listed - although it is offered in 3, 4, 5 and 6 speed versions. Presumably the 6 speed is a 3 speed with a double chainwheel. By 1949 the UK-based Cyclo Gear Company was offering a fulsome range of four different designs.
As late as 1949 there is no front derailleur shown. This was also true of the Cyclo Gear Company in 1949.
Développements are given for both 700C and 650B wheel sizes - which you could misunderstand as being very modern.