RE: Extra Space under/over the Norcold
If you do like I did there is no usable space, top or bottom.  I put a grill
at the top, bottom is not high enough to use.  This will be revisited.  I'll
probably increase the height of the blocks I put under the Norcold and raise
it as high as pratical, providing the space underneath the ue like Mike
suggests.
As for the interior, I found it much easier to use than the Dometic bdcause
of the additional depth.  And even more important, there is room for full
1/2 gallon milk containers in the door AND a special spot to be able to
stand a wine bottle up inside in additon.  I do miss the little top tray in
the door on the Norcold, great for small stuff (and a few cany bars).