In your first picture I can see evidence of plugs on the face of the teak trim. Is it possible that the hatch was secured horizontally through the hatch coaming into the edge of the deck cutout? I would have thought the deck was too thin to do this but I can't see any other reason for those plugs to be there. Do they go all the way around the coaming? Can you see any other reason for them being there?
I, myself, personally intend to continue being outspoken and opinionated, intolerant of all fanatics, fools and ignoramuses, deeply suspicious of all those who have "found the answer" and on my bad days, downright rude.