The roll contains c 100 paper and waxed linen drawings of a mix of mechanical and electrical parts by the following manufacturers: Davies & Metcalfe, J Stone & Co, British Thomson-Houston Co Ltd , Geo. Spencer, Moulton & Co, Desilux Equipment, Worthington-Simpson Ltd, Serck Radiators Ltd, Siebe Gorman & Co, Vulcan Foundry, The Skeefo Ball Bearing Co Ltd, Backer Electric Co Ltd, Metalastik, Newman Hender & Co Ltd, Trico, Crompton Parkinson Ltd, Marston Excelsior Ltd, Taylor Reid & Co Ltd, Westinghouse Brake & Signal Co Ltd and Trico-Folberth Ltd.