Well its 12 years ago but I know what you mean.
Knowing the state of the NHS's IT systems I wouldn't bet my bottom dollar that they would be able to rustle it up and send it to me at the drop of a hat!
Maybe SW would have been well advised (by Penguin et al) to have a copy of the original diagnosis up her sleeve in case everything went pear shaped. I just don't get the sense that anybody at Penguin 'smelt a rat'and took sensible precautions to guard against a worse case scenario.
Anyway, presumably the debate about whether or not SW was informed thst TW had a terminal illness diagnosed im 2013 ( which forms the crux of TSP) could be very easily settled - by the NHS providing a copy of the specialist's diagnosis of CBD as claimed by SW in TSP.