I've actually still got one - found it at a car boot sale a few years ago, clearly not in working order from the way the seller was behaving but I took the chance it might be something simple and offered the contents of my change pocket for it - just under 4 quid. Managed to get it working by bypassing the dodgy power switch when I got home :)

The picture quality is astoundingly bad - I can't believe I used to think that the thing was producing this razor-sharp black and white image! It's horrendously grainy white-with-flecks on a dirty green/grey background that's about half a notch above being static. :)