Finally finished this 15 inch clock today. All time, one of my favorite clocks. Lit up it is simply stunning. Its a head scratcher why anyone would have hog tied the replacement socket onto the back panel, but it was an easy fix. It had a manufacture stamp of 1963. They actually made a smaller version of this design. Ive only seen one in person, at an antique show about 15 years ago. The small double bubble is maybe 9 inches across. Guy wanted $800 for it, and he wouldn't come down from there. I walked...and ive regretted it ever since.