Thanks Okuma. Good idea & something I might have tried if I was braver - lol.
The drive is now with a data recovery company in Peterborough. A local computer shop I was recommended uses them a lot and says they've never failed to recover data for their clients (so fingers crossed). They've give me a diagnosis and quote in a couple of days, but I guess they'll probably do the same sort of thing as you're suggesting tbh. It makes sense.
I should be really happy that orders from the shoot are coming in now, but I just feel sick...
The man I spoke to said it's common for people to consider external drives as 'safe'. That in their experience there are two types of drive - those that have failed & those that will fail. I don't think i'll ever forget that...
Back up, back up & back up again
S
ETA: I always thought that shoot would be make or break for my little business...I guess I can see which one it's likely to be

.