Congratulations and welcome to the forum. Your new trailer is a great size and year, worth restoring for anyone who can handle the time and/or money commitment.
Your reports of floor rot are a concern. The floor is part of the structure of the trailer, bonded on the edges to the frame and trailer walls. It has to be solid along the edges or the trailer will rattle itself apart while driving.
Pictures are a great idea and you'll find a gold mine of information by searching this site. I'd recommend starting
here.
There is also a subform for '66 Overlanders
here. If you get serious about your restoration, starting a thread in that subforum will get good, relevant replies.