Originally Posted by KeelHaulin
To me, it looks like someone tried to replace the window inside the plastic frame. Since the other windows are crazed and this one is not; it also seems plausible. So what they did was cut the plastic frame off of the old window; install new lexan and then tried to re-bond the lexan to the old frame with silicone. The gap you see is where they cut the frame be able to remove the lexan.
Your best bet for getting it repaired properly is to buy a new portlight from a company that makes them like Mark Plastics in Corona, CA. (IIRC)
I was thinking that too but there are the same seams on the other windows. On the other windows it looks like they are glued with super glue or something like that. So I would guess that seam broke when they took it apart. Maybe the new plexi was a little bit too big to fit in the frame so they left a gap. the other gaps are really tight so that would be my guess.
I saw the mark a plastics on another site where a guy used them to replace the windows on his islander.
One problem I have with doing that is that I really don't like the windows.
They don't seem that well made and seemed to be attached in kind of a sloppy way. I guess they have lasted 25 years so they are not too cheaply made but they look it.