In the Historicon dealer hall, there was a vendor called Impudent Mortal. I have purchased things from them before. The Rust line included MDF buildings and terrain pieces that come with photo textured, self adhesive covers. I picked up this set of terrain pieces from them and assembled them yesterday and today.
Another outfit I like is Things from the Basement. Their MDF products are very reasonably priced, and they are very creative. I saw this piece and had to have it.