1975. First British Edition. Unpaginated. Paperback books with pictorial covers. 12 parts with guide leaflet in one slipcase each paginated separately. Black and white illustrations throughout. Binding remains firm. Pages and illustrations are lightly tanned throughout. Paper covers have mild edgewear with curling to corners. Spines in good condition. Slipcase has moderate edge wear with markings to panels and scuffing to edges. Tears to spine ends.