One other idea........if/when you sell your TC, would you be getting another RV? Is your new mattress nice enough to keep and move to your next camper? If so, you could keep the old mattress so you can put it back in when you sell. I have removed a number of things from our Lance (like the over dinette bunk because it blocked the view and cut down the headroom, the mirrored sliding doors for the closet etc.) and I've kept all that junk just in case a new buyer would want it. On the other hand, if you move it to a new RV, you'd have ANOTHER spare that you could move back to the TC.
DutchmenSport - great idea. We used to sleep out on our deck under the stars fairly often but dragging the heavy futon out there got to be a chore. It isn't covered so we can't leave it. But if we had a covered porch/deck, we'd have something similar setup in the summer. Love sleeping out like that.......