I have a mod 1 and made a cover. It was pretty easy and has worked very well for a couple seasons now. I used a white cutting board from walmart as raw material because it was the right thickness and cheap but it's a little bit heavy. Pvc sign board would be lighter and better if you could find a scrap thevright size. Process is the same regardless of material. Start with a full size piece of newspaper and keep folding in the edges until it fits the hole pretty well, then trace that on some cardboard and further refine your pattern. It's really just a matter of fooling with it until it fits well, not hard, just takes a little patience. Then trace on your finish material. I made the latch out of an eye bolt, a few nuts, and a flat piece of metal the size of your little finger. It is the type you turn 90deg and the flat piece slides behind the opening. Whole thing probably took a couple hours to invent and fabricate and cost $10. If i made a second one, it could likely be done in 30min. Just make it!