Vintage Edison Electric Porcelain Sign. Add some retro charm to your garage or workshop with this vintage. Edison Company porcelain sign. Featuring Reddy Kilowatt, this 12 sign is a colorful addition to any gas and oil-themed collection. This sign is perfect as a gift or for any auto shop, man cave or gas station and is an excellent way to display this type of advertising. Vintage Reddy Electric porcelain sign. 12 inches in diameter. Vibrant colors and excellent porcelain.