The other week I finally aquired one of these keyhole strains marked with F.E. in a triangle. This is the fifth one I've seen and all have the mottled greenish brown glaze Elton Gish has speculated that this was a Federal Electric Co. product. I tend to believe this is true because this piece came from Illinois where Federal Electric is located. I had two different colored ones with the lag screw swinging knob hardware but were not marked. I also found another brown one from Pennsylvania that is not marked. You would think there would be a patent for this special design but I've yet to find one. At a time when most manufacturers used a spool for a swinging knob atachment, why use a small strain? If anyone has any strains like this I'd love to see pictures of them. Especialy if they are marked with a different embossing. The search goes on.