Metropolitan-Vickers Electrical Co Ltd was the new trading name given to British Westinghouse Electric and Manufacturing Co on 8 September 1919. The predecessor company had sold its controlling share to the Metropolitan Carriage Wagon Co in 1916 in order to gain membership of the Federation of British Industries. In 1919, Vickers acquired the Metropolitan Carriage Wagon Co, along with its controlling share in British Westinghouse, prompting the change in name to Metropolitan-Vickers Electrical Co Ltd. The American owned British Westinghouse had established its English operations at Trafford Park in 1899, and Metropolitan-Vickers Electrical Co Ltd continued on the same site from 8 September 1919. The company was initially known for its electricity generators, later diversifying into the manufacture of steam turbines, switchgear, transformers, electronics and railway traction equipment. The passing of the Electricity (Supply) Act in 1926 provided a boost to the company’s post-war fortunes, with the creation of the National Grid generating demand for the company's products. In 1928, Metropolitan-Vickers Electrical Co Ltd merged with its rival British Thomson Houston Co Ltd, retaining both names for trading purposes. The following year, on 4 January 1929, Associated Electrical Industries Ltd (AEI) acquired Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd. Again, both trading names were retained, and a fierce rivalry was established between the firms which the parent company was unable to control. In 1931, Sir Felix Pole joined Metropolitan-Vickers Electrical Co Ltd as its new chairman. He oversaw a period of expansion for the company leading into the Second World War. In 1939, seeking a more concise name for the company, the Board of Directors decided upon Metrovicks, which became interchangeable with the official company name of Metropolitan-Vickers Electrical Co Ltd. Under Sir Felix Pole's chairmanship, Metropolitan-Vickers developed new products for the aviation industry and during the war was one of the sites where Lancaster bombers were built. In 1941, the company developed the first British axial-flow jet engine, the Metrovick F.2. Following the Second World War, the company appointed Oliver Lyttelton as chairman, with the aim of increasing the efficiency and productivity of AEI. Despite his success in achieving this aim, Lyttelton was unable to resolve the commercial rivalry between Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd. During his second period as chairman, from 1954-1963, Lyttelton, now Lord Chandos, oversaw the development by Metropolitan-Vickers Electrical Co Ltd of the first commercial transistor computer, the Metrovick 950. Chandos also resolved to extinguish the competition and internal divisions between Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd, and both company names ceased to be used from 1 January 1960, with all subsidiaries going on to trade under the name of Associated Electrical Industries Ltd.

Lancashire Dynamo & Crypto manufactured dynamos, generators and electric motors in Trafford Park, Manchester. The company formed as the result of a merger in 1932 between Lancashire Dynamo and Motor Co and Crypto Electrical Company. The Lancashire Dynamo and Motor Co was established in Trafford Park in 1899. The company manufactured its first alternator in 1901. A few years later, production of induction motors began and in 1910 the company produced the first commercial self-starting synchronous motor built in the UK, at its Trafford Park works. The Crypto Electrical Company was formed in 1904 and commenced manufacturing small electrical motors at Tyers Gate Way, Bermondsey. Within 4 years the company had moved to larger premises before finally moving to a new site in Acton Lane, London in 1912. The Lancashire Dynamo and Motor Company and the Crypto Electrical Co Ltd first associated in 1919, but did not merge until 1932. Lancashire Dynamo & Crypto became the parent company to a number of other small manufacturers of specialist electrical equipment became part of the group, and established new subsidiaries such as Crypto Ltd in Willesden, which manufactured food preparation machinery and equipment, and Crypto Equipment Ltd in Bridgewater, Somerset, a specialist manufacturer of static rectifiers, battery charging equipment and automobile electrical servicing equipment. The success of the business led to the establishment of the holding company Lancashire Dynamo Holdings Ltd in 1951. Lancashire Dynamo & Crypto continued to trade as a subsidiary of the new company. In 1960, Metal Industries acquired Lancashire Dynamo Holdings Ltd. Metal Industries was acquired by AEI in 1967 and the Trafford Park works of Lancashire Dynamo & Crypto closed.

William Skellon worked as a trade apprentice at Metropolitan-Vickers Electrical Co Ltd between 1928 and 1934. during the Second world War his protected employment status meant he could not enlist. He worked on tool development and fitting for Lancaster Bombers at the Metropolitan-Vickers Electrical Co Ltd aircraft factory working on tool development and fitting for the Lancaster bomber. He then went to work in the test bed area used for testing the Rolls Royce Merlin engine which was produced by the Ford Motor Company situated in Trafford Park. After the war he went on to work for several other engineering companies working in various departments related to engineering and production.