After much study, advice and reading lots of threads here, I got up the courage to change the queen in our '98 30' Excella to twins. It has floor to ceiling storage cabinets on each side at the head of the bed with an overhead cabinet between them. See pics.
According to a fellow AS owner who has done interior work, the center cabinet is NOT held up by the side units and is self supported.
We got the street side cabinet out and were working on removing the curb side unit when the center cabinet over the window came crashing down. Actually the aluminum angle brace between the cabinet and the wall above the window held, thankfully, and the unit swung down to about a forty five degree angle before we caught it. My son and I got bruised but no major injuries.
So, now what? Can this unit be fastened to the ceiling? If so how? My plan was to use the upper part of the side units just to fill the gap on each side of the center cabinet, but not for structural support.
I have seen other configurations that have an upper cabinet that spans the full width. Maybe I will need to do that. BTW the 110 volt distribution fuse box is in this cabinet.
Any thoughts or advice is welcome on how to get out of the mess I put myself in.