Success, sort of.
Putting the block back together meant that some wires touched each other - it was unavoidable really. The result was a blown fuse which I located in a block by the battery and replaced. There is another fuse blown somewhere which controls the power to the radio and the power to the instrument panel and digital pod (or two fuses?). I have crawled all over the car with a torch but can't find them - only a fuse block near the drivers feet but they are all intact.
I have seen a thread which talks of a fabled 3rd fuse, but where is it?
Oh yes, and by the way, my tape button doesn't *click* like the CD and Radio buttons, is this normal or is it broken? It doesn't seem to be depressed any further than the other two?