Vintage Skelly Gasoline Porcelain Sign. This vintage porcelain sign featuring the Skelly “S” advertising sign. The sign boasts a beautiful graphic of the S in the center, with excellent porcelain and red & blue color. The sign is in great condition and would make a wonderful addition to any collection or display. This will make the best piece of wall decor for your man-cave, collection, shop, or bar. Vintage Skelly Gasoline porcelain sign. Vibrant colors and excellent porcelain.