From the photos it looks like the wood is warped on the hatch. It may require you to cut some off and add a strip of new wood so the surfaces mate evenly. the weather stripping idea would be a quick fix
SO WE WRAPPED 'E UP IN A MAINSAIL TIGHT
WITH TWICE TEN TURNS OF THE HAWSER'S BIGHT
HEAVED THEM OVER AND OUT OF SIGHT
WITH A YO HO HO AND A FARE-THEE-WELL
A SULLEN PLUNGE IN A SULLEN SWELL
TEN FATHOMS DEEP ON THE ROAD TO HELL
BOTTLE OF RUM!