I found a way to "extract" pictures. :D
Here's the attachment, it's 1 MB, so total is actually smaller than 1.5 mb for cod file. That's assuming you plan to upload all pictures into blackberry, which is unlikely. Average picture size is about 60 to 90 KB.
Last 2 is Lime and Spruce tiled style default wallpapers, I separated it out so I can upload majority in a zip file. Those 2 is (probably) least wanted ones...
EDIT: See below for fixed default wallpapers.