Complex sentence: His father was an architect for the London County Council, his mother a saleswoman for Madame Gray at Machinka & May, London; and then Madame Durrant on Dover Street, London.
Split into simpler sentences: His father was an architect for the London County Council. His mother was a saleswoman for Madame Gray at Machinka & May, London, and then Madame Durrant on Dover Street, London.