One record per source
Give each source its own entry: publication date, author, title, event date and a short description. Preserve uncertainty in the date or identity rather than guessing. A chronology becomes more useful when readers can trace each line.
Separate observation and interpretation
Use distinct columns for what a document says and what you infer from it. A photograph of an event, a participant’s recollection and an organiser’s estimate can illuminate different parts of the same story.
Keep the boundaries visible
Do not publish personal contact information from historical records as a current contact directory. Use original publication links for further reading, and avoid presenting an archival address or phone number as an active service.