The marine grade plywood would be my suggestion as well, AFTER the root cause of the problem the leak or leaks are repaired. My personal issue at this stage of my life is do I have the physical ability to perform the repair? The mechanical understanding for me is not the problem. I have a problem underestimating what my physical limitations are at this stage of my life. Long story short don’t start projects that you are unable to finish as bringing the repair tech a “basket” case always costs more in the long game.
2018 ACE 27.2
Toad 2019 Jeep Cherokee Trailhawk
Roadmaster Falcon All Terrain Towbar