Mark Polk of Mark's RV Garage fame, rebuilt a Yellowstone trailer of that vintage. The total demolition through rebuild is chronicled on You Tube. The first installment of the series is
here. In the videos, you'll be able to see how your Yellowstone is put together.
I rebuilt a similar trailer, a '71 Starcraft. The rebuild thread is linked to in my signature line, "the Cowboy/Hilton". I retained some of the mechanical systems, including the original water system. It is all pictured and explained in the Hilton thread.
If you have particular questions post them up and they'll be answered. BTW, we all like to see pictures of these vintage trailers.