Just to Bring Closure....This is a skate key. It was used to tighten the two jaws that clamped the roller skates to the toes of one's shoes. Ann ankle strap held the back part on. The lower right squarish hold fit over the toggle on the skate, and you turned the whole thing like a wrench or screw driver. Now all the comments should make sens.

Paddle (and skate) safe...
DS

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