Laverda Zane 650/668 Workshop Manual. 668WM Not many of these about now. This is the complete 650/668 workshop manual. It is about a quarter of an inch thick. This contains everything you will ever need to know about these bikes. Even if you do not work on your bike yourself buy it as the dealer that repairs your bike will need it. These were £58 new from Laverda. The photos in this manual are not that good, all other text and drawings are fine.