vfox... it's been sitting in storage on our property since September. I drove it across the (bumpy!) pasture to bring it up to the house on Monday, but that's the only place it's been. No missing rivets/fittings/attachments that I can see. There *was* some previous water damage in the very back corner (previous owner - since fixed), but no new leaks, or missing seals (silicone).
It almost looks to me like a stress fracture... maybe the MH did a weird side to side twist when I drove across the pasture? :-(