This is more to link with Tek Linux and what wendell posts for drive recovery. So I was thinking maybe do some virus removal stuff? Using commands and maybe ClamAV? This is simple stuff yes but I think Wendell could explain the background stuff a lot more and at a lower level, so maybe a high level and a low level one? or link them together some how? While the high level is good I do feel that for advanced topics like this and HDD recovery we should be at say medium level terminology. I would consider my dad at high level and I would not trust him to do a HDD recovery on my system. Just a thought though, and mix in a Raspberry Pi, make some sort of little box that can be used for stuff like this on USB/SD cards, would be great, or maybe even SATA if you use USB and external power (Does the model 2 have enough power for SATA power?)
This would make an interesting topic, not only for linux machines but regarding all os'es... Considering this is covering linux, one thing that could be pointed out is how to remove windows viruses from within a linux environment, since malware today is so sophisticated that antivirus programs barely detect them anymore, u'd have to mount the infected hard drive and trick it to be running in its native environment for it to become active or to 'show itself', so you'll be able to delete it as a root user in the first place... but it's the detection that's the hard part...
We know that lol, but the amount of times I have been asked how I remove viruses is insane, to say I use Kali to do it over Malwarebytes, adding to that explaining why its better to use a live system to remove threats can get annoying. I mean come on, even the local IT shop relied on Norton to remove threats with very low sucess rates, reason I know is because I end up with the machine just after the shop has dealt with it lol.
I would use Sophos over ClamAV myself but that's just personal preference. Although I do have to say I'd be interested in learning how to do this. I also really like the idea @Baz had as well for doing it through multiple operating systems not just linux.