OK, this is the other idea...
Basically, it is a U shaped platform at the aft end of the cabin, with the cabinetry/stowage forward of the legs of the U on either side. The middle of the U will be where the ladder (a telescoping ladder, as before, *not* the ladder in the above drawing) comes down from the companionway. This space - the middle of the U - would have a drop-in platform/cushion that would make it into a double. The pilot berth would extend aft under one cockpit locker as before.
This balances out the weight of the cabinet stowage, makes the double an athwartships berth, and still provides a pilot berth for at sea, when it would be unlikely that the double would be in use were there ever 2 souls aboard. The legs of the U would make for an athwartships dinette, if a table were implemented.
This idea is still very much in the developmental stage, but I think it might be workable. The drawing below is just to illustrate the concept, and is not at all close to scale.
I'm wondering how structural is the aft bulkhead in it's original position? Could a lower part of it be moved aft 12" or so without affecting the integrity of the hull? I think a double should be 48" wide or so. That puts the forward edges of the U arms 2/3 of the way towards the current forward edge of the berths, leaving only 40" of countertop space for each side. The countertops will have a sink, stove, and icebox opening in them, leaving not a lot of room to spread a chart, or whatever else the flat space might be used for - food prep, etc... Nudging the U berth aft would give a little more room to play with.
Edit: Oops! Uploaded a 1024 wide drawing. Scaled it back...