My laptop has returned from the hard drive failure intact, thanks to the Time Machine backups. Yay for automated backups that actually work. Replacing the hard drive was a bit of a production, but I now have a Torx T8 screwdriver and some additional experience in disassembling laptops.
Incidentally, vivianteddybear, if you want me to take another whack at cleaning your laptop out I’m happy to attempt it.