Goulty-
We switched our aft cabin berth athwartships and now have over 7 feet of length plus it's much more comfortable in an anchorage with any roll. We copied the "Amel style" supports and made up a new marine ply "filler" piece. Kept the old pieces so we can easily restore it to the original configuration. Of course, one man's "wasted space" is a long-term cruiser's dream.
Good luck - sorry, but no suggestions for your crew.
Craig Briggs,
s/v Sanagaris, Santorin #68