Thank you. I buried him yesterday (I know it sounds bad. I waited because I wanted to be able to bury him properly and it got dark very quickly the day he went. I also (and this sounds a bit mad) kind of felt he couldn't have gone and maybe I'd made a mistake. Obviously, I hadn't but you know what happens when you lose an animal.
Anyway, I buried him next to Cuthbert (another little mouse we lost about four or five years ago, although not spiny. He lived for much longer than you'd expect too.) so he wouldn't be lonely.