That probably started life as a Walden-Worcester (Stevens Walden) 3/8-inch hex drive L-handle. Bridgeport used the name for a crate tool, and there may be a few other uses out there. But that is very likely Walden. It came with a number of sockets in a little holder.
In the future, if you ever want to do some
'sploring on your own, in the Sticky titled READ B4 POSTING! at the top of the forum there is a link to an A-Z Mfgrs List thread that
@four.cycle maintains here on GJ for everyone's benefit. It's a terrific resource that includes the names and brands of US and worldwide mfgrs. You can search the thread for names when you find them on a tool or just scroll down.
Here are the entries in this case, just for example.