Vickers Armstrong Ltd Erith Supermarine Aircraft Factory check token

A very scarce original circa wartime period 'Vickers Armstrong Ltd Erith Supermarine brass check token'; impressed with identifaction mark 'E1 281'. Good condition.Diameter approx 36mm.The Erith works were part of a larger company that manufactured a wide array of products, including warships, guns, ammunition, marine engines, and general engineering equipment.