This belongs to a friend of mine. He thinks it has something to do with the B & H Railroad based on some research he did on the net and found a B & H Railroad that is purported to be the oldest railroad in the US.
I think it belongs to some type of implement or tractor category, based on my experience and reading so much about them right here on ToolTalk!
Here's the measurements....open end is approx. 9/16". The double sized other end measures 3/8 square on one side, and 5/8 or 11/16 on the other. The overall length is approx. 5-1/2" or so.
What say you wrench gurus out there? Rarity? Any value? It's in pretty good shape. I really have no idea, these type wrenches are out of my realm of collecting.