Below the pull out pantry in our '85 Sovereign
is a space about 6" high, the width of the pantry, and over a foot deep. This unused space was present in all models with the pull out pantry, and for all I know is still just empty space on the current models.
When I needed just a little more room for a new 12 volt
Aquajet ES water pump than was available for the old pump, this hole turned out to be very useful.