So, for now at least, I have simply returned the deadlights in almost-original configuration. Yet I really liked having them able to open, so I have been thinking on how to implement that.
One consideration I have had always was that prior to going out to sea, I would like to have 'sea shutters' made and in-place; basically large 'covers' over the deadlights which were affixed to the house, providing a much smaller window area, and basically serving to keep serious impact from striking - and possibly pushing in - the entirety of these large holes in the house.
So I think I can make them opening for at-anchor, dock, or day sailing usage, while utilizing the sea shutter idea for offshore. Below are my first scribblings of ideas. I am trying to make it as simple as possible, considering amounts both work involved and finances. I would also like to retain as much as possible to original look of the boat.
First idea involves building a "lip" all around the deadlight area which would serve two purposes: to hang the needed hardware from, and to deflect water streaming across the deck/house sides so that it cannot directly strike the gasketed seal, forcing in water via 'normal' (ie not storm or big seas) pressures. The portlight would attach to the upper lip with hinges, and have hardware on the inside that would 'cam down' to seal the port shut against the gasket. The 'glass' would pivot out and up, preventing light rain from entering the cabin. The lip would have built-in threaded holes to allow affixing of the sea shutters.
The second idea (pics #2 & 3) illustrates the beginnings of a second solution, which would be to pivot the glass not from the top, but in the middle, the upper part swinging in, the lower out. It would pretty much have the same features as the first idea.
Still thinking on both of these...