Some time in 2015-ish era, CA was closing the aft port light and the clamp that screws it down hard against the gasket failed catastrophically. I can't find the picture, put the metal failed, leaving the hatch not fully closed and — consequently — dripping onto the aft berth.
Here's the link to the Beckon Parts page: https://www.beckson.com/latches.html.
We had what they call the "safety twist knobs." Lots and lots of ‘em.
The replacement is the latch.
The tricky part is getting the old knob out. There's a pin that secures the assembly to the port body via two "pin bosses."
There are two approaches.
Here: https://www.beckson.com/retro.html. File out the crimp in the threads and unscrew the knob.
And the alternative, which is to bang out the old pin and put in an entirely new assembly.
Banging out the old pin is hard. Really hard. A few would not budge. One of the bosses was cracked, so we didn't want to bang on that any more than necessary.