Vintage Harley Davidson Motorcycles Porcelain Sign. This vintage porcelain sign showcases the iconic Harley Davidson Motorcycles. Measuring at 12 and featuring the Vintage Iron lettering, this Harley sign is a must-have for any gas & oil or collectibles enthusiast. The bold colors make this sign a standout piece of advertising for any man cave or garage. This sign will enhance your man-cave, collection, motorcycle shop, or garage. Vibrant colors and excellent porcelain.