At that time there were 9 different examination boards in the country, with each of them free to set its own syllabus for O-Level English Literature. However each of those boards offered several different syllabuses to schools, so there were at least 20 or so English Literature syllabuses operating concurrently. So you could find another 20 people, who all sat their O-level English examination at the same time as you, with no two people having studied the same texts.
As an indication of the sort of texts that you might have encountered around that time though, the 1974 syllabus used by the University of Cambridge Examining Board included the following in one version of their syllabus:
*Shakespeare - Twelfth Night
*Shakespeare - Macbeth
*Chaucer - The Pardoner's Tale (in the original English)
Dickens - Great Expectations
Forster - A Room with a View
Barnes & Egford - Twentieth Century Short Stories
Golding - Lord of the Flies
Hewett (Editor) - A Choice of Poets (Owen, Edward Thomas, Auden, Wordsworth, Keats)
Arthur Miller - The Crucible
A variant of the above syllabus was available though, replacing the texts that I've marked with an asterisk by these works:
Gray - Elegy Written in a Country Churchyard
Keats - The Eve of St Agnes
Coleridge - The Rime of the Ancient Mariner
Ten years later, in 1984, the same board listed these texts for one of their syllabuses:
Shakespeare - The Merchant of Venice
Shakespeare - The Tempest
Chaucer - The Nun's Priest's Tale (in the original English)
Charlotte Brontë - Jane Eyre
Hardy - Far From the Madding Crowd
Arthur Miller - The Crucible
Hunter (Editor) - Modern Short Stories
H G Wells - The History of Mr Polly
Hewett (Editor) - A Choice of Poets (Tennyson, Hardy, Elliot, R S Thomas)
An alternative syllabus from that board for 1984 had this list of set works:
Shakespeare - Macbeth
Shakespeare - A Midsummer Night's Dream
Hardy - Far from the Madding Crowd
Remarque - All Quiet on the Western Front
Tennessee Williams - The Glass Menagerie
George Orwell -1984
Henry James - Washington Square
Twenty-one Great Stories (Edited by Lass & Tasman), to include these . . .
Steinbeck - The Pearl
Pirandello -War
Jack London - To Build a Fire
Carl Stephenson - Leinengen Versus the Ants
James Joyce - Eveline
Mark Twain - What Stumped the Bluejays
Ray Bradbury - There Will Come Soft Rains
Saki - Tobermory
Wilbur B Steele - Footfalls
Ambridge Bierce - An Occurrence at Owl Creek Bridge
Poe - The Cask of Amontillado
Maupassant - The Necklace
Conan Doyle - The Adventure of the speckled Band
Thurber - The Secret Life of Walter Mitty
There was also a third syllabus offered by the Cambridge board in 1984. For that there was only one formal examination, covering . . .
Shakespeare - The Merchant of Venice and
Shakespeare - The Tempest.
Schools opting to use that syllabus could submit their own selection of other works, to be approved by the examining board two years prior to the examinations period, with assessment being carried out internally by the school (as both normal coursework and set essays) and then moderated by an examiner from the board.
I took my O-level English Literature exams back in 1969. I can remember studying loads of boring WWI poets (Graves, Brooke, Sassoon, Own, etc), alongside All Quiet on the Western Front. (Our newly-qualified English teacher had written his university thesis on the authors of that period, so we got lumbered with having to study them!). I can also remember studying Lord of the Flies and Animal Farm but one or both of those might have been included in earlier years at school. (The same applies to Henry V).