There have been various classic periods of lunar work, from Galileo’s time, through the German and British periods of the 1800s and 1900s, to the Apollo era. I was fortunate to be a bystander in the later period and had occasions to meet and work with many of the prominent people who studied the Moon at that time. In The Modern Moon - A Personal View I included a cast of characters section, in the space below I will record short remembrances or impressions of others who have studied the Moon.
Dai was my boss from 1962-6 when I worked on the The System of Lunar Craters, a crater cataloging and mapping project at the Lunar & Planetary Lab. Dai was a bachelor who had come from England to work with Ewen Whitaker and Gerard Kuiper on the lunar atlas projects. He was an expert mathematician, apparently self-taught, and would sit down at his desk and write out in ink his papers from start to finish including all the derivations of equations. He arrived at work at about 10 AM and would walk in with a coffee cup and start talking. He loved to recount stories of when he was in the British army in North Africa in WW2 and how crafty Rommel was. He also talked of the amateur lunar community in England (often in response to my questions), frequently criticizing them for ignorance and craftiness. He recounted once how he noticed Percy Wilkins (then Director of the British Astronomical Association Lunar Section) copying details from a Mt Wilson photo onto his Moon chart and later presenting it as details he observed. Dai loved trains and apparently had a large model railroad set up in his home.
I met Kopal in 1971 at a lunar conference in Greece. He was very active in the 60s and early 70s, writng popular books and organizing and editing professional conference proceedings. He directed a british project in the 60s to determine topography by shadow measures from movies taken a Pic du Midi in France. Those elevations are used on the US maps that are in the Times Atlas.
I knew Barbara when we both worked at Kuiper’s Lunar & Planetary Lab in Tucson in the 1960s. She was one of the 3 British astronomers (Dai Arthur and Ewen Whitaker were the others) that Kuiper brought to Yerkes and then Tucson to help with lunar mapping and editing projects. Barbara edited most of the series of books that Kuiper organized - they were the fundamental compilations of what was known about the solar system (e.g. The Moon, Meteorites and Comets), the sun and later out into the galaxy; they were the predecessors to the Univ of Az Space Science series. I last saw her in Houston a decade or more ago. She seemed to be living near JSC and would ride her bicycle near there. I don’t know how she became interested in lunar transient phenomena but her compilations occupied her for quite a while. No one else at LPL (except for one grad student - not me!) believed they were real.