At the beginning of the project I purchased new official copies of the genuine workshop manuals, volumes 1-5. Unfortunately these did not include the commercial vehicles and the volume 6 supplement is not available. The commercial range has a full chassis and rear leaf springs. Torque settings, in particular, were an issue. Through an online search I was able to find that the National Library of Australia in Canberra has a copy. For a reasonable cost and satisfaction of their copyright policies, they copied the entire volume to an electronic format for me to download. I received it today. It will make the build a lot easier.