I had some time this week and used it to upload a near-mirror of the archived version of the GOG Covers website. You can find this reuploaded version at: https://ludiantiqui.com/GOGcovers/index.html
I also spent a lot of time changing the filing system from its original hexadecimal form to folders based on the first letter of each game title (excluding the word The). It's certain there are a few broken links from the change but you can search through all of the uploaded images at https://ludiantiqui.com/GOGcovers/images/
Unfortunately the archived version is from April so there are definitely some missing covers but I'll try and get to adding them and fixing any broken links soon™.