In 1994, I embarked on a PhD study to examine, for the first time, what happened inside the classroom during history lessons in pre-Second World War Britain. Previous studies had relied largely on a study of textbook content and official curricula guidance, without stopping to ask how and whether such materials were actually used in pre-war schools themselves. My study not only looked at the textbooks and official curricula guidance, but also sought to get inside the classroom of the past by conducting oral history interviews with former pupils and teachers, and through a systematic review of the professional teaching press. This case study provides an account of one practical aspect of a 3-year-long PhD project, taking the reader to the heart of some specific situational and methodological problems that arose in the course of the research. The case sheds light on the particular challenges in using oral history interviews to elicit valid and reliable testimony about seemingly everyday and commonplace events in schools that took place more than 60 years prior to the interview. Thinking about such challenges leads to a more general consideration of the relationship between oral history methods and ‘traditional’ documentary methods in historical research. Particular attention is paid to the use of props as a method of aide-memoire, as a fruitful way of drawing out broader and deeper testimonies from interviewees.