Well I had to use yoga position 55 to get some of the photos but hope this helps
The top two and bottom left were taken in portrait mode so you will need to rotate to the right to view correctly.
The hatch photo
was taken from underneath the false floor looking up.
As you can see they have just cut out the area marked in your boat
, put a support ply panel beneath and installed the push button latch one side and a couple of small stainless brackets the other side -job done