I want to replace two items on my 1973 O'Day. I'm not even sure what they are called sooo, I could use some help. I believe they are port lights. One is located on the starboard deck just behind the bowsprit. The other is located in the cockpit, again on the starboard side, behind where your calf is when seated. They are both 5 inches round and screwed into the fiberglass. I think they were orginally white but faded to yellow, cracked and the interior plastic fell out. What are these called and where might I find replacement parts?