The Internet Archive has a collection of ImageShack archives at https://archive.org/details/imageshack.us?sort=-publicdate, which go back to 2012 (by upload date, not sure if that's the earliest image date or not). As ImageShack is one of the largest sources of missing images, this is a potentially valuable resource for restoring missing ones.

Hopefully (though I'm not optimistic) it might have some pre-2012 images, too. There are a lot of mid-2000's ImageShack links.

But how to use these archives is not abundantly clear. They understandably don't make it super-easy to start downloading 100+ GB of images. Looks like it might use SQLite, but more research is needed.