I found this tool recently, initially thinking it was a particularly robust file handle:
When I cleaned it up, though, this was stamped on the steel end, which is actually a hex socket of a peculiar size:
It says: Carre Company. "Lift the Dot." It was clearly intended as a driver for the specialized "Dot" fasteners made by the Carr Fastener Company of Cambridge, Massachusetts. The driver exactly fits the fasteners shown below.
The firm eventually becamed United-Carr. I've put more information about that company's history on a previous post on Dudley Locks. The question in my mind is why is the name spelled "Carre" on this earlier tool?
Another curiosity: I discovered that I have an old grease gun made by this company, when they apparently had a plant in Hamilton, Ontario. I've never seen any information that they made anything other than fasteners.