Pre-khmer rouge cambodian recordings appear to be pretty rare. The Jaques Brunet recording seems to be pretty ubiquitous, and the great luobiniya blog has a couple others, but this Angkor-Vat record is not on discogs, and I can find absolutely no other mention of it anywhere on the internet, despite the fact that Maurice Bitter was a rather prolific ethno-recordist whose voodoo ceremony recordings are rather famous. It inlcudes a song composed, if not actually sung, by the "king-father" of cambodia, Norodom Sihanouk.
DL