The Lewmar size1RE opening ports on #1925 - a 2001 MKII were crazed, leaking and generally a mess. I tried replacement parts but Lewmar has Standard / new Standard / new old Standard etc. After ordering a couple versions of the wrong replacement parts I purchased entire new ports from MauriPro. 
When I removed the frames of old ports I discovered whatever sealant Catalina used when the boat was new had dried up and disappeared. Other than some gray dust there was nothing sealing the frame to the hull, I probably could have eliminated the leaks with a new bead of butyl tape. 
The original lenses were crazed, screens long gone, interior trim rings gone yellow so replacement was my best option.
If your ports are drippy but otherwise acceptable rebedding the frame may be the simple solution.
The replacement ports came with new screws that were a bit too long, I used the originals and they squeezed the bead nice and tight to the hull.  Each port took about 20 minutes since it was a direct replacement.