My random translations of the photo captions, clockwise from top left are:

• Juy 51 1951
• Rigidex 1951
• Rigidex 1951
• Rigidex 1951

• Publisher: New Cycling
• Document: New Cycling May 1981 - '81 Derailleur Collection
• Date: May 1981
• Derailleur brands: Simplex
• Derailleurs: Simplex Juy 51, Simplex Rigidex