Rhomboid? Is that anything like a Rumba?
I have been thinking about doing the same thing. There are so many little places that they just box over. I have opened up most of them in our TT saving this one for last.
In our case, we don't gain much since the hot water heater, pipes, and the freshwater tank are all under there..... but it would help a little for sure.
I did find a nice, rather large area to the right of the water tank and opened that up from the outside storage area.
2008 - 189 FBR
2007 Jeep WK Limited CRD