Don't know anybody itching to buy a new drive you could borrow for a day?
I'd still give it a shot. You'll at least get the first portion and find out how recoverable the rest might be. GDB will just stop when it runs out of space, it doesn't hurt anything.
I haven't seen another program that's as good at recovery. There are other pro-level recovery products but they work the same way. "Repairing" is harder and more error-prone since once directory structures are damaged much of the work is best guess. That means you might run a few passes before you get effective settings, and that's not possible if you're changing the directory each time. Try GDB on what you can, then use norton. Norton & other repair tools can be effective if the damage isn't bad.
If the problems were caused by a master/slave issue there's a possibility the damaged files were never written, and data was lost in driver timeouts. GDB could give you a clue here even if you don't set it loose recovering what it finds.