OK, thanks for the feedback, I really appreciate
I agree with the forty years and I had this in mind too but I don't know how much the boat was really used in the last forty years (i know it saw about zero use in the last 3 prior to me acquiring it).
And after a year using it here in SF there are definitely some part of the headliner that are deteriorating (stress cracks, some there before but seems like they are extending). Although not in the same place this sort of made me reconsider the veracity of this hypothesis.
I'm also considering some cruising in the future and I had read that strengthening the hull is a worthy endeavor. It's also prime real estate I found there, especially on a 8' wide boat and I was considering sealing the sides to store stuff in this place