Vintage Sinclair Gasoline Pump Plate Sign. This vintage porcelain sign features the iconic Flintstones characters advertising Sinclair Gasoline. The sign’s vibrant colors of red, green, orange, tan, black and brown make it a great addition to any collection of gas and oil memorabilia. Measuring 12 inches, this sign is in excellent condition and would make a great addition to any collector’s display. The sign’s durable porcelain construction ensures its longevity and will be a focal point of any room. Don’t miss out on the opportunity to own this unique piece of Sinclair advertising. This sign will enhance your mancave, collection, shop, or garage. It is your chance to own a piece of Sinclair advertising. Vintage Sinclair Gasoline porcelain sign. 12 inches in diameter. Vibrant colors and excellent porcelain.