Thanks to all who have responded. I will be pursuing the dealership to remove the (new) AC and let me see within the mounting and I will do the recommended inspection by removing the interior housing for the AC. Somehow I don't think I'm going to get that far due to other circumstances. We bought this unit with the verbal and written word that the roof was in good shape...no leaks, no water damage. We'll see how the dealership chooses to honor that contract. I just want to be educated if/when they try to deny a roof replacement. An independent rv tech strongly discouraged anyone from walking on the roof for fear they would fall through it and be injured. Please continue to send me your thoughts and things I can do to help me understand what I need to do next.