I came across Wally Bryant's project on Stella Blue, where he fitted aluminum plates on the outside, filled wide plywood, and then installed 4 Newfound Metal ports in each side. Very nicely done but still, four small ports where there had been two larger portlights.
I've done similar on another boat so that approach works for me, but I was wondering if anyone had found a particular opening port that more closely fitted the holes, i.e. just 2/side. Once in a while you find ports on sale, overstocks or discontinued, whatever, butof course whatever size you have in mind, they're usually 1/2" off in a way that makes it impossible. I'm sure you know the feeling.