There's two approaches, I add my cheekplates after the deck is joined to the hull and epoxy them to both the deck and hull. I like the extra support and structural strength. If you stripped over enough of your cockpit opening when you stripped your deck, you might have enough ready-made strip panels from the cockpit cutout to make your cheekplates. That's what I did on my latest project and ended up with these nice curved cheekplates.