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

• Skylark
• Skylark
• Lark W
• Lark

I think that the correct labels might be:

• Shimano Skylark
• Shimano Skylark
• Shimano Lark W
• Shimano Skylark (DD500)

• Publisher: New Cycling
• Document: New Cycling May 1981 - '81 Derailleur Collection
• Date: May 1981
• Derailleur brands: Shimano
• Derailleurs: Shimano Sky Lark red (1st style), Shimano Skylark (DD500), Shimano Skylark (SL10), Shimano Lark-W (D280)