What you were told is mostly to entirely true. Chassis stuff is Ford and quite readily available. Appliances and a great many pieces of hardware (including windows, awnings, doors, etc.) are generic RV stuff and not too hard to come by parts or replacements. There may be a few odds and ends that were specific to the maker, particularly things like fiberglass molded exterior pieces, which may be hard to find. Usually it's possible to repair or otherwise make do. I would not generally worry about buying an RV built by a company that's out of business. (There's no guarantee that any unique parts would be available even if they were still in business, for that matter.)
