Just did some more examinations.
Here is the AO mapping for the 7C.
Notice the parts I have circled and pointed to!
Edit the colors to match them more closely.
On the 7B you'll find the same type parts. So edit those in any paint program.
The circled part is the upper half of the ballast tanks.
To check? Do a pattern on those upper parts with a color taken from the lower sections.
Then check in Game.
You can do some CRAZY stuff by messing with the O01 texture files!
Try placing red stripes on a few parts once.
Check the Bismark AO01.dds!