Re: New member, new project
My philosopphy is if it isn't broken don't fix it. My 98 Ford/Collins has a good solid floor and the steel beneath is in good shape with minimal rust. At the age of yours it might need a new floor but check it closely from beneath and above. Use an awl or ice pick to check for rot.
One thing I didn't do on mine, and wish I had, was remove the inner sheet metal and re-insulate the walls and ceiling with foam board. Removing the inner skin enables you to weld to the structural elements where you make openings or close in windows.