Seem to remember that the lunar photometer using a photocell was used extensively by a Lunar section member Lawrence Fitton to measure albedo changes in local lunar topography. I think there was an interesting “discussion” in the LCC about the validity of the method with a member (David Jewitt) who became very famous as the first astronomer to recover Comet Halley at its 1986 apparition. Old days old memories!
Denis Buczynski
British Astronomical Association
Supporting amateur astronomers since 1890