Not sure what your confused about? The position report example given is correct? Remember CAP413 is the complete RT manual and caters for people flying things other the cessnas hehe.
In the example given, Fastair 345 is the a/c identifier, you don't need to say the type again as the controller will already have this information from when you joined his freq (from the response to pass your message) He then states his position, Wicken, and the time, 47. His level in this case is FL280, and his next point is Marlow at 57. It is all very brief to save time on what is usually a bust freq.
In your example of what you think you need to say there is a lot of unimportant info. Like I said you don't need to say Cessna as the controller already knows this, you don't need to say where you or from or going as the controller already knows this too. You do need to give your position, the current time and your altitude. then give your next position expected and the eta for it. NOT the eta for your destination, unless that is the next point you will report.
Does that make sense? Remember a position report is just an update to the controller of where you are.