Thanks to everyone re polish products. In the end I went to my local motor factors shop today and got a new tube of Autosol. I used it with my dremel flex line with a polishing mop. It certainly made a big difference. If you look closely you can still see some of the original rust pitting but not many people are going to be looking for it.
While I was looking at the engine I noticed that it seemed to be a bit low at the cab end, just didn't look correct. Off came the body, removed the chassis brackets mounts and put a shim under each one, it was only a 1mm but it looks a lot better now.
