Yours are the oval bronze portlights of the earlier Hatteras Yachts. The Fuller lights are the rectangular injection-molded plastic ones of the later yachts. Fullers are still available. I don't know who made the bronze ones, and I have tried a little bit. Do you need the wingnut or the wingnut and shaft assembly? I have found stainless wingnuts which fit the shaft, but these are not as large as the OEM. I could use a couple of the originals as well.
Be careful of forcing these nuts if they are stuck. Because they are bronze it is easy to twist the ears off. I recommend penetrating oil and low-grade heat such as a soldering iron. Torches burn the paint off.
These are great portlights because they never wear out and are infinitely rebuildable. Next time I replace my screening I will try glueing fiberglass screen onto the screen frame instead of soldering copper screen onto the frame. The copper seems to get brittle after about 15 years.
Let us know if you find anything.