The hinges look like those on a Vetus hatch on my 1977 Islander
It needed new hinges and the stretch rubber and plastic "dogs" that tension it shut.
Vetus was no help at all in finding either the hinges or the dogs
. Yes, it is a 40+ year old product, but it was disappointing not to be able to get parts
A friend fabricated new hinges for me out of aluminum
that are much more durable than the original plastic.