505 appears to be part of one of those old hand exercizer devices--
i.e., the grip enhancers.

506 is a wire crimper, isn't it? It looks like something I've seen
phone technicians use.

502 looks like part of a mop attachment, which means it's probably part
of a car engine

503 is one of Tom Delay's favorite toys. He's been looking all over for
it and without it, no one listens to him any longer.

504 is an ear grabber extender. It's for elderly women who want to grab
you by the ear but don't feel like getting up. It's got a button on the
other side which extends it by three feet.

506 is an early (rejected) prototype for the soup ladle.