My DW and I are looking to purchase a 1990 GV U280 with a 3208 Cat with 160k miles. I have been reading this forum for information the last few nights (does make getting up harder in the morning) and the more I read the more questions I have. Such as can you walk on top of these MH, and the AquaHot is it a mystical device or just a heat exchanger. This will be our...