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. Polly Premium Motor Oil. 12 inches by 8 inches. Vibrant colors and excellent porcelain.