Rare Vintage Heavy Enamel Blue Circle Cement Advertising Sign.. I cant find another one like this approx 1930s. It is a nice size not too big. Diameter 61 cm or 2 feet. Nice clean condition as per pictures. The item “Rare Vintage Heavy Enamel Blue Circle Cement Advertising Sign” is in sale since Monday, February 4, 2019. This item is in the category “Collectables\Advertising Collectables\Advertising Signs”. The seller is “paul_g67″ and is located in Chessington. This item can be shipped to United Kingdom.