The textures are applied to flattened stretched cubes placed against the wall. As for uploading, there is nothing really to upload as they are all separate boxes. [:)]
Emmanuel, yes you are correct, that is the site I used for my textures, by the way I didn't find your post boring, on the contrary, it was very interesting!
If it is helpful here is an exploded view, the foreground box is the one used to make all the shapes, then textures are applied.
db4tech