For our paper anniversary J gave me a gift certificate to the Secondhand Rose, a cool store in New York City that deals in antique wallpaper. They carry original William Morris prints, other Arts and Crafts movement artists' papers, and Art Nouveau papers. They also carry other vintage papers (more 50s & 60s).
MP just sent a link to Imports from Marrakesh. They carry tiles, textiles, and wrought iron works.
More tiles--gorgeous Art Nouveau tiles at Tile Heaven & a list of handmade tile designers.