You need to get the book titled The Lister CS Story by David Edgington, Several sources in GB for it. Not every change is detailed but all of the important ones are. The factory records for the late engines, post about 1955 or so were all destroyed in a fire so you will be able to find out little about the engine you purchased. For the earlier ones David can tell you when it was shipped and to whom and if it was ever back to the factory for updates.