DX Diamond Motor Oil porcelain sign features the iconic DX Diamond Motor Oil logo in bold colors and excellent porcelain. The sign has large DX Marine gasoline lettering. Whether you are displaying this sign as part of your collection in your man cave, shop, bar, or garage, or giving it as a gift, you can also browse my other auctions for more vintage gas, oil, aviation, automobile, motorcycle, and hunting signs. Vintage D-X Marine Gasoline porcelain sign. 12 inches in diameter. Bright colors w/ porcelain on both sides.