The rotting floor is a major consideration. See threads on floor replacement. On my '83 the floor had just been replaced when I bought it, and this was a huge factor in my decision process.
As for the the ice-box vs 'fridge question, the purchase of the desired refrigerator
is the main consideration... you can see the info about the relatively straightforward installation if you look in the Document Center of this forum and read the page or so in the Burro
Owner's Manual on "how to do it." The hardest steps will be putting the vents into the side wall behind the 'fridge and running in the gas line. If you already have the gas stove, adding another branch for the 'fridge is pretty easily accomplished. Keep us informed and good luck with your project.