Vintage Shell Gasoline Porcelain Sign. This vintage Shell porcelain sign is an excellent addition for a gas and oil collector. The sign features large lettering and the iconic colors of Shell Gasoline. Measuring at 17 3/4″ x 6 1/4″, this sign is a great addition to any vintage memorabilia collection. The sign is perfect for display in any garage, sign collection, shop or man cave and is sure to be a great center piece. Vintage Shell Gasoline sign. Thick porcelain on both sides. Vibrant colors and excellent porcelain.