So if I was a noob and accidentally deleted the backup files I keep on my computer of my site's layout.html - how would I go about getting them back? I know the "generate layout and menu files" link won't do it, and even clicking the link that says "history" won't give me the file that I previously uploaded.

If it's been uploaded to your site through the Advanced Layout page, it's in that history link somewhere, you just need to remember about when it was uploaded. Those files in the history do not delete, it is a complete and comprehensive list of every time you've uploaded a file to your site.

It'll take some work.

Keep in mind, the "Generate Layout and Menu File" generates the basic layout, and does not generate it for the drop-in templates.

I guess the two that I tried from the history link were just bad or corrupt or something, the older ones and the ones I uploaded today are all intact. Now that I think back on it, I can vaguely recall uploading some "highly experimental" things sometime in November which would explain it.

Anywho, I furiously dug through my backups and found it there. Very convenient that I was gifted with a new hard drive about 3 weeks ago and backed up everything then.

Crisis averted. Breathe out.