Westland Helicopters was a British aircraft manufacturer. Originally Westland Aircraft, the company focused on helicopters after the Second World War. It was amalgamated with several other British firms in 1960 and 1961.
In 2000, it merged with Italian helicopter manufacturer Agusta to form AgustaWestland. In 2016, AgustaWestland merged into Leonardo, where it became the company's helicopters division under the Leonardo Helicopters brand.
The above information was from this Wikipedia article about Westland Helicopters, where more information can be found.
The CAGE code is for the Yeovil site when occupied by Westland; a new CAGE code applies while occupied by Leonardo.
The Westland Helicopters Ltd. logo is from one of their film productions.
The link below for Leonardo's article on the Yeovil site.