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

• Route Leger 1939
• Monobloc 46 1946
• Tour de France (Italy) 1947
• Champion 46 1946

The image labelled 'Champion 46' might be better described as a 'Champion du Monde 46'.

• Publisher: New Cycling
• Document: New Cycling May 1981 - '81 Derailleur Collection
• Date: May 1981
• Derailleur brands: Simplex
• Derailleurs: Simplex Route Leger, Simplex Champion du Monde 46, Simplex Monobloc 46, Simplex Tour de France (Italy)