Well, no responses indicates nobody has heard of them.
While perusing through the book "Communications Receivers" by Raymond S. Moore, I did find one that has a similar dial, but as it is a very low-res image, it is hard to tell.
Quote:
General Manufacturing Co. Chicago, was a coil manufacturer. They put out a kit receiver using their coils.
Though the band coverage does not match, the dial almost looks like it has the same brand marking. Though, again, it is really hard to tell.
-Steve