An Imageshock account by the name of themillenniumfalcon has posted pics of so called concept art, which according to a source close to the site The Star Wars Underworld, says are “legit.” The site also mentions that another site called MakingStarWars.net has been describing these concept photos before they leaked and they seem to fit the descriptions. Here are some of the photos that were posted by the Imageshock account:
https://imageshack.com/user/themillenniumfalcon