I have found this list of Camps used to house Italian prisoners in Britain obtained by an Unknown person from them in 1984. It was posted on a postal history site in 1996. I am uncertain about the total accuracy of it as it lists Grizedale Hall Camp No 1. I thought that was German Officers only. It may be a list compiled over time in Switzerland as no Base Camps were opened numbered 201+ until after 8 May 1945. http://www.forcespostalhistorysociety.org.uk/journal_archive/journals-239---228/journal-229o.pdf I hope it helps you with your research.