Sheet 1 Wong Tin GSGS 3868 Third Edition 1949. Grid and graticule change only. Printed UK 8/49. Previous editions 1929, minor corrections 1939, 1945 (Grid change only).
Sheet 3 Wong Kong GSGS 3868 Third Edition 1949. Grid and graticule change only. Printed UK 8/49. Previous editions 1929, minor corrections 1939, 1945 (Grid change only).