Hi paxman (I did wonder when I saw your site name if it was a tip of the hat to his nibs). You've set yourself quite a task but some of us would love more Old Boys Books on CB+ and what better place to start than Magnet. You'll have noticed that there are already a few on site and some of us had converted and posted a few. My problem was that I only have a slow, free convertor and some of the files wouldn't convert. I have noticed that more .cbr files are appearing on Friardale and that can only be a good thing, although I think they are mainly in the Nelson Lee and Thriller sections. As for contacting them, you've tried with no luck and as we always credit sources, where known, we shouldn't be causing offence. After all, it's spreading the word and that's a good thing.
On a personal note, I'm a big Bunter fan also but read a lot of Nelson Lee.
So, go ahead, making sure you're not duplicating files already on, uploading only.cbz files, and making sure you don't find yourself a slave to the computer.