56. Every person whose name and address, permit number or trade mark are indicated on a product kept for sale, or on the container, label or wrapping of such product, as a person engaged in the preparation, production, conditioning, wrapping, supplying or distribution of such a product, is presumed to have prepared, made, conditioned, wrapped, supplied, distributed or sold such product to the keeper of the product at the time when and at the place where the keeping has been ascertained or, as the case may be, at the place indicated on the product, container, label or wrapping of such product.