This is a cast iron tractor seat manufactured by Blackstone and Company Limited of Stamford. It would have been brown or black originally. They are popular as wall art, like this one owned by a previous employee of Blackstones, or used as bar stool seats. They can be bought online, although watch out for reproductions. Blackstone tractor seats were produced by Blackstone & Co of Stamford, Lincolnshire, a prominent agricultural engineering firm operating between 1889 and the 1930s. These iconic cast-iron seats, often featuring the "Blackstone & Co, Stamford" inscription, were standard on their horse-drawn implements and early tractors, and are now popular antique collectibles for garden furniture. The company, based at the Rutland Iron Works, was a major employer in Stamford for over 100 years, becoming Blackstone & Co Ltd in 1889, focusing on farm machinery. The cast-iron seats were designed to be mounted on various farm implements, such as hay rakes, before being used on early tractors. The distinct cast-iron seats were produced during the height of their agricultural implement manufacturing, generally ranging from the late 19th century up to the 1930s.