i found a website, which although a little out of date~the photos are from 1991, it has very good photos of the interior of the castle at cardigan.
having just watched a show on the television that's recent, i'm amazed, that the place looks the same as it did back in 1991.
The only difference being in 1991 the owner was still living in the tower that was incorporated into the Georgian house, and that Georgian part must be more run down now.
There's a bit of the history of the castle on the webpage as well, including about it being the first place the Eisteddfod was held.
http://www.castlewales.com/cardigan.html