I am adding all the details to the top side mold. I thought this would be easier. But many of the edge pieces have 3-D curvature, and I couldn't just bend them out of thin pieces. For example, here is one of them. I start with a cube that contains the part I want, and glue paper patterns to two sides. I cut it on a bandsaw in one plane, then keeping the stack together, cut it in the other axis. Here is the cube with all the cuts done.