Question: The M22 Locust was designed and produced by the company that was a manufacturer of what types of vehicles until the early 1960s?
Context: Graiseley Electric Vehicles were produced by the British company Diamond Motors Ltd of Wolverhampton.  They had previously made motor cycles, but began producing battery-electric road vehicles (BERV) in the mid 1930s.  They were best known for their three-wheeled pedestrian controlled vehicles, although they also produced conventional four-wheeled milk floats, and later manufactured industrial trucks.  The company went into liquidation in the early 1960s, although the marque was used by two other companies until at least 1972. Opel Automobile GmbH (Opel, ] ) is a German automobile manufacturer, a subsidiary of the French automobile manufacturer Groupe PSA since 1 August 2017.  In March 2017, Groupe PSA agreed to acquire Opel from General Motors.  The acquisition was approved by the European Commission regulatory authorities in July 2017.  Opel's headquarters are in Rüsselsheim am Main, Hesse, Germany.  The company designs, engineers, manufactures and distributes Opel-branded passenger vehicles, light commercial vehicles, and vehicle parts for distribution in Africa, Asia, Europe, and South America.  Opel designed and manufactured vehicles are also sold under the Vauxhall brand in Great Britain, the Buick brand in the United States, Canada, Mexico, and China and the Holden brand in Australia and New Zealand. The Asquith Motor Company Ltd. is an English commercial vehicle manufacturer of hand built replicas since 1981 and originally based in Braintree, Essex.  The company was founded by Bruce West, who designed the logo, created the name and designed all the early vehicles.  His concept was to create modern vehicles with the potential of mass advertising through the appeal of historic vehicles.  In 1984, West sold the moulds to Hunnable Holdings of Yeldham, Great Yeldham, Essex. The Marmon-Herrington Company, Inc. is an American manufacturer of axles and transfer cases for trucks and other vehicles.  Earlier, the company built military vehicles and some tanks during World War II, and until the late 1950s or early 1960s was a manufacturer of trucks and trolley buses.  Marmon-Herrington had a partnership with Ford Motor Company, producing trucks and other commercial vehicles, such as buses.  The company may be best known for its all-wheel-drive conversions to other truck maker's units, especially to Ford truck models.  Founded in 1931, Marmon-Herrington was based in Indianapolis, Indiana, with a plant in Windsor, Ontario, and remained in Indianapolis until 1963.  It is now based in Louisville, Kentucky. The M22 Locust, officially Light Tank (Airborne), M22, was an American-designed airborne light tank which was produced during World War II.  The Locust began development in 1941 after the British War Office requested that the American government design a purpose-built airborne light tank which could be transported by glider into battle to support British airborne forces.  The War Office had originally selected the Light Tank Mark VII Tetrarch light tank for use by the airborne forces, but it had not been designed with that exact purpose in mind so the War Office believed that a purpose-built tank would be required to replace it.  The United States Ordnance Department was asked to produce this replacement, which in turn selected Marmon-Herrington to design and build a prototype airborne tank in May 1941.  The prototype was designated the Light Tank T9 (Airborne), and was designed so that it could be transported underneath a Douglas C-54 Skymaster transport aircraft, although its dimensions also allowed it to fit inside a General Aircraft Hamilcar glider. Chambers Motors was the first automobile manufacturer in Ireland.  The company built vehicles by hand featuring high-quality components designed and fabricated in-house.  Passenger cars were made to suit doctors and wealthy businessmen, and commercial vehicles were produced for duty as delivery vans, ambulances, and hearses.  A key feature of the vehicles was a unique design of epicyclic gearbox in the rear axle.  Chambers Motors employed around 75 people and built approximately 500 vehicles in 25 years of operation. The General Aircraft Limited GAL.  49 Hamilcar or Hamilcar Mark I was a large British military glider produced during the Second World War, which was designed to carry heavy cargo, such as the Tetrarch or M22 Locust light tank.  When the British airborne establishment was formed in 1940 by the order of Prime Minister Winston Churchill it was decided to develop a large glider which would be able to transport heavy equipment in support of airborne troops.  General Aircraft Limited were chosen in January 1941 to develop this glider, which they designated the GAL.  49 'Hamilcar'.  It was designed to transport a single light tank or two Universal Carriers.  A number of problems, which included vacillation by the War Office on the number of gliders that it wanted and poor management by GAL, led to delays in the production of the Hamilcar, and the first production glider was only assembled in mid-1943.  These problems were only partially solved, and production of the glider continued to be slow, hampered by difficulties in finding suitable locations to store and construct the Hamilcars once their parts were produced.  A total of 344 Hamilcars had been built when production ended in 1946. Malkotsis is the trade name for "Technica S. Malkotsis A.E.", which has historically been the most important Greek engine manufacturer, surpassing several engine (mostly diesel and semi-diesel) manufacturers that flourished in Greece in the 1920s and (mostly) 1930s, like "Dimadis-Kanakis" in Volos, "Peteinaris" in Kalamata, "Sideris", "BIO", and others in Athens, etc.  Located in Piraeus, before World War II "Malkotsis" produced various types of industrial machinery.  After the war it produced industrial machinery for several Greek companies, but it progressively focused almost entirely on diesel engines, soon becoming the largest company in its field.  "Malkotsis" engines found use in a variety of industrial applications, while its boat engine models became legendary for their reliability.  A series of electric motors was produced as well.  Its "EM" Diesel series (designed in collaboration with a British consulting firm) included engines specifically designed for powering of vehicles and was employed in "Malkotsis's" own farm tractor models ("Malkotsis EM-2" and "EM-4") introduced in 1959.  The tractors were produced for only a few years, due to lack of funding and other problems related to a complete lack of state support.  The company faced financial problems later, due to competition from cheaper imports, and was acquired in 1991 by Drakos-Polemis A.E., a pump manufacturing company which used all "Malkotsis" infrastructure for its production purposes. Seddon Atkinson Vehicles Limited, a manufacturer of large goods vehicles based in Oldham, Greater Manchester, England, was formed in mid 1970 when Atkinson Vehicles Limited of Preston was acquired by Seddon Diesel Vehicles Limited of Oldham.  In 1974 the firm was acquired by the American giant International Harvester, and in February 1983 it was purchased by the Spanish group ENASA which made it a subsidiary of Pegaso.  In 1990 it became part of the international commercial vehicle concern Iveco who used the brand for various types of specialised vehicles in the United Kingdom.  The range of models produced included "EuroMover", "Pacer" and "Strato", which are aimed at refuse collection, recycling and construction operators. AK Hellas (the initials standing for the full name of the company, 'Aggelopoulos-Karkanis O.E.') was a Greek manufacturer of light trucks and other metal products.  It designed and produced two basic types of vehicles - all three-wheelers with 50cc engines, taking advantage of a favorable classification as "motorbikes" according to Greek law.  One group of models it produced since 1965 were light trucks with "motorcycle" structure (steering and controls), a type of vehicle also produced in Greece by "MEBEA" (by far the most successful), "Mego", "Alta", "Saracakis", "Pitsos" (a big home appliances manufacturer), "Markal", "Naxos" and others.  The other group of models were "proper" micro-trucks, with "automobile" structure of steering, controls etc.  It was in this category that "AK Hellas" became the biggest truck manufacturer in Greece, leaving behind "MEBEA", "Delta" (a product of "Attica"), "Minicar", "Zamba" and other smaller Greek manufacturers.  The company's "T200" model, using a "Sachs" 50cc 4.8 hp engine and with a payload of 150 kg was produced between 1968 and 1975 with three different cab designs and in several versions (including van models).  According to Dimitrios N. Aggelopoulos, several thousand units were produced, while other branches created by the same entrepreneur, were involved in production of pleasure boats, biological cleaning units, telephone booths, phone switchboards, generating sets, helmets, storage tanks, prefab container houses, wind turbine blades, irrigation systems, etc.
Answer: trucks and trolley buses