Vintage Polly Gasoline Porcelain Sign. This vintage porcelain sign features Polly the parrot. The sign measures 12 inches and has a colorful design with excellent porcelain. It is a great piece of gas and oil advertising memorabilia for collectors, retro man cave decor or your shop or garage. Vintage Gasoline porcelain sign. 12 inches in diameter. Vibrant colors and excellent porcelain.