Vintage Mustang Oil Porcelain Sign. This vintage sign from Mustang Oil features their iconic mustang horse and is perfect for collectors of gas and oil memorabilia. Whether you’re a fan of vintage advertising or simply appreciate the history of Mustang Oil, this sign is sure to be a conversation starter. It’s a great addition to any man cave, garage, or collection. Vintage Mustang Oil porcelain sign. 11 3/4 inches in diameter. Vibrant colors and excellent porcelain.