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

• Grand Prix
• New Skitter
• New Skitter
• Grand Prix

I think that the correct labels might be:

• SunTour Gran-Prix with no 'd'
• SunTour Echo
• SunTour Echo
• SunTour Gran-Prix again with no 'd'

• Publisher: New Cycling
• Document: New Cycling May 1981 - '81 Derailleur Collection
• Date: May 1981
• Derailleur brands: SunTour
• Derailleurs: SunTour Gran-Prix, SunTour Echo