Thanks for that - I'm hoping to get the bits sorted to apply for his service records from the MOD in the next week or two, and in the meantime I'm trying to read up on what happened in Malta during the time he was there.
I came across a book in Googlebooks the other day, but stupidly didn't bookmark it or take a note of the title, and now obviously I can't find it, but it seemed to have a fair bit of info about the siege - unfortunately only a small part of the text was actually included on the Google books page though.