heres a pic of what i did so far. incase anybody doesn't have the drill with wire wheel attachement like smartchick. i used a wire brush and it worked pretty good. going to use spray foam to fill in the side handles. don't feel i need them. i used paper to outline this opening as best as i could. then cut the piece out of scrap aluminum siding. easily bendable to the shape. but very strong in this shape. i then used an angle grinding to make it perfect fit. Hot glued it from the back and top and grind it smooth.
fiberglass would have been the way to go. but its going to be under fabric. y work so hard?