These are Flip Pins, advertised new IC style pins for PCB projects. They come in 20 pin, 14 pin and 8 pin versions (for 40, 28 and 16 pin sockets).
PET ROM/RAM boards which need to overhang adjacent chips which may also be in sockets.
PET diagnostic boards, which are designed to plug into the 6502 socket of a Commodore PET. These now form something which looks even more like the IC it replaces.
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