Lisa, you have landed on a forum dedicated to all-molded fiberglass towables, i.e., "egg"-type trailers. Ours are constructed with a self-supporting molded fiberglass shell, and most are lined with closed cell foam or some kind of marine headliner material- no wood framework, wood paneling, or wallpaper.
A quick Google search on "Okanagan" leads me to believe yours is a conventional framed trailer with a laminated fiberglass skin. The repair issues are different when it comes to the kind of leak-related damage you describe with mold inside the wall structure. You may get suggestions from members who have previous experience with your build type. But you will probably get more and better help on a general RV site such as iRV2.com
Sorry to hear about your difficulties. Hope you are able to get some help!