Well, made progress on the hatch.
Photo 1, I removed the fiberglass skin and mounted the balsa cutout onto it and trimmed it to within about 1/8". You can see where I made a flat to which the hinge will be mounted. It is tapered too, so the hinge line will be as close to the surface as possible.
Photo 2, a test fit.
Photo 3, This is a tool that I really like. it is a set of mini rabbiting bits. It will make 3 or 4 different size rabbits with an adjustable depth. I'll use this to create a recess around the hatch opening that the fiberglass skin will fit into.
Photos 4 & 5, I made a small template that matches the curve of the fuse. I only used this to draw lines that will be 1/32" past the balsa for a trim guide.
Photo 6, After trimming the fiberglass, I found the hatch opening was a little off.

Scott