Rough chronology from the fifties went:
Essay Questions - 7 to be answered if I remember correctly. You can still find sample books in UK reference libraries.
Early/Mid 70's Multiple choice - main difference being penalty marking. Marks taken off for guesses/mistakes.
Next up penalty marking removed countered with a 5% change in the pass mark IIRC
Final trauma was the switch to the JAA multiple choice exams which had a very anxious birth - our archives cover that period as the schools tried to get the syllabus, feel and feedback for the new exams nailed. All of which seemed a moving target for a while.
There are some experts ground school types around who can expand, correct and fill in details to the above.
Regards
Rob