We just removed the underhung tanks that were an add on to our
1954 Safari. I hated that look. It consisted of two large tanks, one fresh water and one combo Black & Gray.
Instead, we added a fresh water tank under the side dinette seat, a black water tank under the front toilet which was raised above the floor with a shorter stool, and a gray water tank which consisted of plumbed back and forth pipes within the frame hidden by the belly pan to accommodated gray water. I will use a blue boy when needed or other means since there is no shower producing gray, just a sink.