Short answers, pulled from the story.
William Collins, Sons was founded in Glasgow in 1819 by William Collins, a Presbyterian schoolmaster, in partnership with Charles Chalmers, the younger brother of Thomas Chalmers, the minister of Tron Church in Glasgow.
Collins Crime Club was a crime fiction imprint that ran from 1930 to 1994. It published all but the first six of Agatha Christie's novels starting in 1926, as well as the British editions of Rex Stout's Nero Wolfe books and many other titles from the Golden Age of Detective Fiction.
Collins merged with the American publisher Harper & Row in 1990, forming HarperCollins. News Corporation had become the sole owner of Collins in 1989 before completing the merger.
Britain in Pictures was a series of social history books published by Collins between 1941 and 1949, designed to boost morale during the Second World War. Contributors included George Orwell, Graham Greene, Vita Sackville-West, Cecil Beaton, and John Betjeman, among others.
Collins founded the New Naturalist series of nature books focused on the British Isles in 1945, with the inaugural volume being Butterflies by E. B. Ford. The series proved remarkably durable, with three new volumes appearing in the summer of 2015.
Collins Education is the third-largest educational publishing house in the United Kingdom. In 2010 it acquired three publishers: Belair Creative, a specialist in art and design resources for primary students; Letts and Lonsdale, a major publisher of revision guides; and Leckie & Leckie, a Scottish educational publisher.