Object Identification

Hi everyone,

I'm new here, so I'm not sure if this is the correct place to post this, but:

My boss find the below object in a railyard in Detroit, covered in rust obviously. It weighs about 5lbs and is about 5 in X 3 in. Is it some sort of car coupler, something used for cargo tie-down or... something else? Any help is appreciated. Thanks!

It'd help if there was a ruler to compare sizes. The top might be an old brakeshoe pad...