You are right, odd angles and profiles, make for odd-ball compound angle cuts, but you seem to have a good handle on it. What are your plans to make the hatchlid waterproof at the sides and the hinge? Are you planning on skinning it with aluminum? Looking forward to your construction pics, and wonder if you are planning a return trip to the West Coast when it is finally built. Good luck, you have a great start.
Roly