@nick, most bad hard drives I have encounter do not trip SMART monitoring.
When SMART errors are triggered, it is often too late and much damage has already occurred.
The big 3 manufacturers WD, Seagate, and Hitachi have DOS bootable utilities that are customized for their particular drives to perform extensive surface tests and can try to remap bad sectors and/or move data from a bad sector to a known good sector.
On a hard drive, there are often "good" sectors that are used as reserved and not mapped as usable so that these utilities can try to "fix" your drive before data is ultimately lost.
You should add this to your guide, as what you have included, although informative, does not really repair or recover your drive.