My aunt worked with Mary Lobel on the original Atlas (I inherited her copy) mainly as a "retirement project" - it was fascinating to see the research laid out on her table and the various sources that informed the whole exercise. Things like the details of a court case between neighbours indicated that XYZ street was 1 foot wider at a particular point than previously thought or similar findings. I remember at the time wondering why they couldn't publish just the maps as they were fascinating (with the academic papers that made up the rest of the Atlas). Fortunately, a decade or 2 later that's what they did.