Skycreens - Skyshades

I was happy with the Oceanair blind that I put in our H400.  I think it is lewmar size 44 and the fit was exactly right.  Lewmar's own blinds seem to be available now at a significantly lower price and if I was buying now I'd probably try them.

If the ceiling surface is not flat, and doesn't have a headliner the blind won't work so well, but I saw one owner added some foam gasket to compensate.

I attached a photo of ours - the ceiling here (fwd cabin) doesn't have a headliner so you can see some light coming through at the edges, but this doesn't bother us.

I update this thread.
The right sizes for H355 hatches are 44 for the front cabin and 60 for saloon.

But I didn't find how to undo and take the standard lewmar inside trim off. I can undo the white levers very easilly but they are still well stucked. Is it glued ?
Any idea how to remove it (see photo) ?
I'm thinking about cutting the edge in order to have a flat ceiling and then screw the Oceanair skyshade.

No, I haven't yet.
I left this job for the winter. Waiting for that, I've just screw the fore cabin skyshade over the original trim. It works as a temporary solution.
I note that you were able to cut the trim with a blade. I'll try to do the same.
Many thanks.