It is indeed Lewmar. You can get the knobs and other hardware including new portlights (the plastic windows themselves) as well as new gaskets which are important to address any water intrusion. You can get them here at this site, at Defender and several other places. You might want to shop based on pricing because there are differences. What you want is the Lewmar portlight style used on 1997 and earlier models. It's identified in the description. There are four of five sizes of the portlights and you have to get the properly-sized gaskets. The knobs and other parts should be identified for right or left latches. It's not cheap but I replaced everything on my 1997 321 Oceanis and it looks a lot better. I even changed out some of the knobs and latch hardware on my Lewmar overhead hatches -- its amazing what the sun, saltwater and less-than-good care by the previous owner(s) will do to the appearance and functionality of portlights.