W.r.t. www.archive.org

If you take a look at old pages there you will see that they are only storing the html page. If the page has embedded images which are still stored on your server then they will be displayed in the page.

This means that picscout is not looking at an image stored at archive.org, it is looking in your images directory for images.

So it is worth going to your server and cleaning out the orphan images.