The scan shows three of the 10 cards (in a 4-7/8″ x 8-7/8″ cardboard case) whose cardboard cover is subtitled “Sketches and photos of 10 geological features of Hong Kong by Prof. Chan Lung Sang”.  As this cover had been opened before, the tape that originally sealed it has left a small mark on the back of the cover–not disturbing the cards themselves.  Note that some of these locations are a UNESCO Heritage site but the cards do not say so.  Cards:  Grades 1.  Case:  Grade: 3