I have an oldish London residential phone book, which lists several D Wallises, abour four of whom are (or were) in north London. If you want to send me a personal message with a little bit more about your project, I'd be happy to follow them up, in the hope of getting at least a forwarding address. I'm also registered with some UK-based people-search services which might be worth trying.

I did actually read the book, by the way (the one where the oldies topped themselves). I'm pretty sure it was turned into a film, but didn't see it. But I fear it will be many years since Dave got his last royalty cheque, M Ted.