It sounds like you definitely have a broken display assembly on your hands. A quick online search took me to this site that sells replacement Display Assemblies for your device.
Unfortunately, as you mentioned, we do not yet have a guide that shows how to install a new display assembly. Luckily, the motherboard installation guide that you mentioned will get you pretty darn close! If you look at the last picture in the motherboard guide seen here, it looks as if the only other part you will need to remove is the gray and black plastic plate protecting the display assembly. You can even see the orange board underneath that looks just like the one in the product image on the first site I linked to.
If you feel like getting your feet a little wet in the DIY-repair world, we say go for it! You can even take a picture or two to add to a new guide for showing other people how to install a new display assembly, if you so desire!
Hope this helps! Good luck, and let us know how it goes!