Ultraman,
You may find the biggest chore of working on the companionway hatch is getting it off. In the course of replacing fuel tanks or travelers many of us have removed the hatches. Even on different 35-3s there seems to be variability in how the system is assembled. Some folks were able to remove the slider without removing the sea hood. We were not.
Jeff, Also. I think that you can separate the tape from the tank without cutting it. Use a putty knife or chisel and the bond will release. This would make reinstall even easier and no worries about cutting liner. Hi David, Did you need to remove your sea hood (which for me includes the...
ericsonyachts.org
In this thread Christian details working on his sea hood and includes several other links:
The Ericson sea hood covers the hatch over the companionway when the hatch is open. Such a hood is the easiest way to prevent water from entering the forward end of a sliding hatch, and to protect it from feet, lines and other abuse when open. The hood is made of plywood sandwiched between...
ericsonyachts.org
Elsewhere he has discussed making (or having made) a new curved acrylic panel for his slider, but I don't recall where. Acrylic will bend with heat. It's a common technique for manipulating the material.
I'm thinking that crazing is not just a surface condition that can be buffed out. Our hatch plastic is in relatively good condition. I suspect this is because the PO had a dodger rigged most of the time. The two big forward hatches were toast and we had them rebuilt by HatchMasters in Norwalk, CT.