Just remember I discussed this matter with the Gebo people some years ago and - unfortunately - the acrylic of Gebo portlights can't be replaced.
Joe
That’s exactly the kind of reply I had from various replacement portlight manufacturers when I asked them about replacing the acrylics for my Lewmar portlights, and in the end I did the job myself.
Yes, I could buy replacements from Lewmar stockists, but I didn’t want to fork out more money than I thought was reasonable for the job, and particularly because Lewmar had changed the fitting for the portlights such that buying new Lewmar acrylics might still not have enabled me to renew my portlights without the further expense of buying new portlight frames.
So I would ask very specifically why can’t the Gebo portlight acrylic be replaced, what exactly is the difficulty that leads people to suggest the acrylic cannot be changed? After all, Gebo fitted the acrylic into their portlights so what is it that they have done, that cannot be redone? I faced the problem with my Lewmar Portlights and determined a work around that actually worked, maybe you could do the same by explaining the specifics of the problem along with a photograph or two so that the rest of us can look at it and help if we can.