Here's the link. When I purchased a couple of years ago the price was just over $50. https://www.greatlakesskipper.com/innovative-product-solutions-boat-deck-hatch-520-035-8-x-14-polar-white (View Post)
Longer screws and fender washers keeps ours in place. It's a 2020 320S, so it's not the same as yours, but may offer some ideas. It's not visible from the ground. (View Post)