These were made in Chicago's Motor Row at 1458 S. Michigan avenue as an aftermarket replacement by a company called DoRay. For decades, they were a lens supplier for cars, trucks, stop lights, fire signs, etc.
These fit all Ford cars in 1961. The base is 6-7/8 outside diameter, mounting screw holes 6-1/2 center to center. New, never used and perfect condition. The center clear is glass, the silver is aluminum, and the red is plastic.