[snip]

with picture this summer to show how and if it works. My question is, when
: you cut out the already fiberglassed hatch panels, do you put some epoxy
: on the edges to keep moisture out. You can't build the edges up too much
: or they won't fit. That really seems like a stupid question but I need to
: hear it from someone. Thanks.

You'll buy a little room with the thickness of your saw, probably
enough for a layer of glass even. I'd use thin epoxy to allow for
flexing & warping. You can always plane off a pinch more.
Arlen