I suppose technically this occurred yesterday, as I write this fast approaching 4am after nearly 12 hours of panic, stomach-sinks and desperation.
Firstly the important part; the following should be added to your "WTF-OMG USB Stick of Oh-fuck Panic Recovery", immediately.
I say this as, of the many I sifted through, it's the only one that gave me the messages that dragged me from my quite depressed state:
|Red Text of Love|
As you can see from the screen-shots, it's no oil-painting to look at, but damn if it doesn't do the job (hopefully... it's still copying files). Ignore the ISOs and the free-trials and the "this is what you could have recovered if you paid £30". It's the old adage of "K-I-S-S":
Keep It Simple, Stupid.
Once you realize what you're looking at, it is quite simple to navigate the text options and while it wasn't able to re-constitute the partition table, it did at least detect them and allow me to traverse the folder structure to initiate the copy.
I've accepted it's not going to be a 100% recovery - the fact that the disk geometry is damaged (which is what is preventing the partition restore) says to me something nasty happened in there but the fact I'm getting files out at all is pretty good.
Now to buy more disks for in-house mirroring... It would be nice to buy stuff because I want to, rather than because I need to.