Hello, I see that Nortek was mentioned in this thread so I thought I would join the discussion.
When you've had a scratch of this nature, the magnetized coating is literally stripped from the platter surface. The bit patterns represented in that region have been destroyed and no present or future technology can ever get them back.
Secondary damage occurs when the magnetized particles that used to be attached to the surface fly around the inside of the drive. They can stick to the heads and cause further, less visible damage, and they can also alter the values of bit patterns elsewhere on the drive. This of course irreversibly corrupts that data as well.
If you are lucky and the system region of the drive is not damaged, recovery of the non-scratched areas is a remote possibility. Given that you have taken a picture of the platters, I would assume that you have opened the drive in a non-clean room environment. Naturally, this also severely diminishes the chances of success.
If you are interested in pursuing recovery from this unit, please feel free to email
support@nortek.on.ca to open a case.
Regards,
Chris