theratbox.kira-kira.net is the subdomain. If you have old links, they will still work if you change "www.theratbox.com/whatever" to "theratbox.kira-kira.net/whatever". That will work for all stories, for the index, and for a couple weird things like Mulciber's page.
Otherwise, you can just go to the old fic index, and all of that works just the same it ever did.
I actually went to the site last night to grab something quick and was startled by the...you know, lack of site. I knew it was coming, but I still sadfaced for a few moments. And now I have to try and figure out where all the 8 million places I've listed my website are.