This is what is being used to glue and seal all the bits together.

This will be used behind the jack mounting plates as it will give a better seat and not allow so much flex like the putty being squished and oozing out.
Here's the rub...if you try to remove the plates without cutting the adhesive it could rip off the fiberglass, so you need to use a thin spackle knife to pry/cut loose.
This stuff has been used in marine industry for ages. I am glad Lentz is using it.
Staples, screws and glue at almost every joint in the structure.