Gordon Edward Lawrence Roper

Dunlop Aircraft Tyres Ltd. manufactures and wholesales aircraft tires and tubes. Its products include retread, radial aircraft, radial and bias tires. The firm supplies tires for different types of aircraft in the civil and military aviation market. The company was founded by John Boyd Dunlop in 1889 and is headquartered in Erdington, the United Kingdom.

Castle Equity Ltd. engages in manufacturing of industrial rubber goods, rubberized fabrics, and miscellaneous rubber specialties. The company is headquartered in Birmingham, the United Kingdom.

Part of Castle Equity Ltd., Turret Bond Ltd. is a holding British company that provides finance services through its subsidiary. The company is based in Birmingham, UK.

Part of Castle Equity Ltd., Castle Mezzanine Ltd. functions as an investment holding British company. The company is based in Birmingham, UK.

Tyre Holdings Ltd. is a holding British company founded in 2017 that operates subsidiaries which manufacture and retread aircraft tires. The private company is based in Erdington, UK and has subsidiaries in United Kingdom.