Longman's Bridge Series consisted of popular books with the language simplified for learners of English as a foreign language. The Bridge version of Kingsley Amis's Lucky Jim dates from 1963. There's a great deal of period charm in William Burnard's illustrations,and even more in the glossary thoughtfully provided for those who get stuck on some of the more obscure English phrases.
Other titles in the series included the expected classics (Dickens, Austen) alongside more unusual choices like books by crime writer Michael Innes and Sir James Jeans' introduction to physics The Mysterious Universe. Most intriguingly, there's also an anthology called Stories Grim, Stories Gay.