Techwriter,
First things first, find an RV dealer that knows about this coach and get his appraisal. Anything else is just a guess....
Next and I mean NOW, find some nice white Duck Tape and make the holes weather proof. You don't know what is inside there and it might get really bad if it is left open.
You don't give us any idea what your capabilities are, but the ladder is just a search out and buy new tubing (~500$ it is an RV). If I still did glass repair, I could make the surface damage pretty for about a day (8~1K$+ paint= 12~1.5K). Don't count to hard on on my numbers, I have been out of the boat business for a few years. Again, I don't know what is inside there, so I could be WAY off.
Matt