Alden,
I have noticed those trailers with the dropped belly and thought they would be a great portable house. If you wish you could install a door that would be closer to the ground level and skip the excess stairs or floor over the inside belly and use the drop area for storage. Lower center of gravity might not be so important in Maine but it can be significant in Oklahoma. The drop belly trailers I see come through this are are normally household moving trailers. It sure looks pretty straight for a used trailer that's been in industry! If you are going to strip it down to the deck/floor there are a lot of used drop deck flatbeds for sale. Please keep us informed if you go for it.
Bryan