I removed the head door on my boat - same issue as you have - how to improve storage and usefullness for one person. Curtains work great. I removed the sink in the head to add more storage space as 2 sinks 8' apart make no sense to me. My CS27 is designed to seat 6 at a table - I don't think I ever will and if I do they can eat off their laps. I have made the table smaller fore and aft and will probable remove one leaf (the one that opens in the passageway forward. On my boat I changed the galley by replacing the alcohol 2 burner with a propane 3 burner/oven stove and moved the sink inboard closer to the companionway so it will be easier to use and when I haul I will move the seacock farther inboard so it will drain on both tacks. The hanging locker opposite the head will be converted to better storage with shelves. It currently has a door that alternatively closes the hanging locker or the v-berth off. I will replace this door with a curtain for the v-berth and maybe zipped canvas for the locker. Above the settees in the main cabin to starboard there are three teak lockers. This will be changed to a locker at either end and bookshelves in between. The engine access was a large angled fibreglass affair with teak steps in molded recesses. When accessing the engine you had to find somewhere to put it and if it was a bit rough at the time it was dangerous. I made it more vertical and added a small removeable 2 step ladder with storage under each step. The engine access door is now on lift off hinges and for normal access there is nothing loose - but just lift it and it comes right off. Because my engine is fairly low (horizontal 1 cyl Yanmar) I had room above it to buils in a removeable toolbox. I am adding some pics - first a pic of a Hinckley pilot I got some ideas from. Second is a pic of a Morris I patterned most of the galley after. Third and fourth are pics of my boat when it was in progress. The bare wood is now white laminate like the Morris.And a link to a Nicholson modified by James Baldwin I got some ideas from. I found the best ideas came from cruising Yachtworld and looking at interiors.
Atom Voyages | Nicholson 31 Refit
scroll down and look at the interior pics
ps - What kind of boat are you thinking of buying? Bet it doesn't have an Atomic 4