SIde cabin shot
Back forward cabin top shot
Right side after adding clutches, and 2nd winch
The upper is a side shot of the area at the top of my cabin. I believe your Islander is a bit smaller up there vs my 30' Jeanneau, but you can see what I had before I removed the "horn/jam cleat" on the top of my cabin top. With the clutch's that are in front of the winch.
The clutch closest to you in the pic, is for when I use my 110 or smaller jibs. As I have two jib tracks. One down below for my 130, 140 and 155 carbon, and one in between the wood rails you see on the outside of my cabin and the mast for smaller headsails, that lead aft thru that clutch and to the winch. At some point in time, the winch you see, will move a bit more inward, and a bigger winch, probably a 32 will go to the outside approx where the cleat is for the small jibs.
I prefer this style "horn cleat" for lack of better wording, or knowledge of what that cleat is, probably should look it up online at WM or equal eh?
The inner clutches, are for my boom vang, cunningham, empty for spin pole ring, Jib then main halyards and 110- jib. Other side is set up simaler, but I have the first three lines are for outhaul/reef lines, spin and 2nd jib halyard, boom lift, spin pole lift and 110- clutch. I also have two winches there, a single speed 14 on the inside, and a dual speed 16 on the outside, that will go inside when I get bigger winches for the outside.
Hopefully how I have things setup will help you come up with a plan for you cabin top, and what may or may not work.
added two more pics, left now looks similar to the right side, with one more triple clutch set to the right towards cabin entry, with double stacked organizers per side. You can also see the inside jib tracks too. I should point out, I do race my boat, so I probably have a few more lines than most will!