Richard,
This is bit dated, but I have some picture of the Factory Tour in 2011. I use them to help figure out how things are routed. The shower and black tank vales are pretty easy to get to, just un-bolt the under belly in front of the wheels where bottom level changes. The galley tank value and fresh water tank, your best bet is to cut a access hole.
Here is a link to my Factory Tour Pictures:
https://plus.google.com/photos/10904...ner=pwa&sort=1