Riggern8,
Welcome to the forums and congratulations on your find. We think you're off to an excellent start by finding this forum. We see a significant improvement in our efforts between our first restoration (before we found the forums) and our second. Keep reading posts and asking questions, someone here has run into whatever your facing and has solved the problem. What's even better is, they'll share what worked and what didn't.
Here's a link to our '68 project, if interested.
https://www.airforums.com/forums/f39...er-155180.html
It sounds like you may not have a lot of the old interior components, so let us know if you need dimensions or info. Our trailer is 4' shorter than yours, but probably pretty similar. Starting with a blank slate is an exciting prospect, but think through where the exterior openings are located (refrigerator roof vent, furnace vent, storage compartments, water heater, etc. Those locations can be significant as you figure out what you want the layout to be. It's a lot of time and effort to move a refrigerator vent to the other side of the trailer, for example. It can be done, but probably wouldn't be worth it.
Good luck and enjoy the project phase.
Roy and Marie