Thanks again guys.
Not much progress on the image itself, but I've knocked out a tiny video capture in answer to Caesar's prompt. When I say small I do mean small - and probably not a lot of use - but I'm still practicing with this sort of stuff. Hopefully it will get better with future offerings. Nothing on a par with Jon Hodgson's excellent vids, but it's not a competition (or if it is I concede now). Do go look at them if you haven't already - wonderful stuff. Mine is just an attempt to explain different approaches to image making.
You'll find it here on the rather sparse so far 'tutorials' page of my site, because I'm not savvy enough to get it on YouTube or anything clever like that. Click the image to either open or save the thing. It is about 5mb so you may find it works better by downloading it first - I found the sound was gone when I tried playing it online. Mind you with my waffle that is probably a bonus.
Small video available HERE http://nickillus.co.uk/page12.html