Well, there's good news and there's bad news.
The first thing I did was label the stereo wires and then cut them. Hopefully that will mean I can find them, reverse engineer what they are from the back of the stereo and then splice them into a generic block connector. Then I removed (well broke) the last clip on the heater cables and pulled them all through.
Finally it was time to actually start moving the dash.
I started off following the instructions, trying to disconnect all the connectors. There were about 6 that connected the loom that was part of the dash to the column, and I could actually reach these ones so I disconnected them. That meant that the dash could move a bit more, and I realised that there were loads hiding behind the dash. Given how much of a struggle doing them when I could see them, and where I could actually get tools on them, I didn't fancy my chances of disconnecting the hundreds that were lurking out of reach under the dash and behind a bunch of other cabling.
So I took the easy way out, cut the 3 cable ties that connected the dash loom to the dash, and just yanked the dash off the loom, leaving that still in the car. After much effort and swearing, the dash moved off the loom and appeared to be free. I almost got the whole thing out, but there were some (more) random attachments that I've no idea what they are holding it fast. Once I'd removed the random panel holding them, I could finally try to get it out of the car. There were several times during this process I thought it was going to break in half, but miraculously it didn't. So before I start the jigsaw puzzle of putting the broken shards of dashboard left in my footwell back into the dash, here's what came out.
The central piece is almost entirely disconnected from the main bit that passes across the car, the whole section around the steering column is cracked to hell (possibly from resting on the steering column where I fought everything else), there are loads of missing points where there should be mounts for screws, and there is a giant crack running across the top just in front of the driver. Aside from that, it's not too bad!
I need to get hold of some epoxy and CSM and start putting some strength back into it - once I'm happy it won't fall apart in my hands I'll have to start working out how to add all the mounting points back in so that you can attach the clocks, heating etc sturdily. I'm guessing that's going to take a little while templating up bits of steel (in some cases working out how to add the mounting holes back onto the heating stuff too). After that's done, I guess it will be time for the flocking!
I also need to disconnect all the bits of that loom, clean all the connectors so you can push them together and take them apart without enormous force.
Once I've done all that, I can consider re-uniting the dash and the loom and putting it back in the car - don't think I'll be driving it for a little while!