Inner wall template cutting

I am attempting to follow the sandwich method in Steve Fredrick's manual. The sandwich frames are completed (for the most part). I have already gang cut 4 sheets of 1/4" plywood to the teardrop shape using the template. I am now looking at cutting the inner walls down to allow for the ledge that the ceiling and spars will sit on. As I read the instructions, my understanding is that I need to mark a concentric line on the inner wall that is approximately 1 5/8" short of the outside wall edge. Then gang cut the two inner wall plywood sheets to to that smaller, concentric shape. These sheets will the be used as a template to cut the wall sandwich frame down, creating the remaining part of the ledge.
The part that is hard for me to visualize is when it comes to the galley portion of the wall. It obviously doesn't need a ledge with no spars in that area. So, can I assume that the ledge cut out of the inner wall plywood would end at the rear portion of the doubled up spar for the galley hinge with sandwich wall aft of that left alone and matching the original template profile? There seem to be a variety of ways to skin this cat. I have seen a few examples of builders cutting a square notch through the entire wall to sit the galley hing spar into, or that is the way it appears. That looks like a method I'd like to use. I just want to make sure I am understanding this clearly before cutting the sandwich frame, and possibly ruining several hours of labor.
The part that is hard for me to visualize is when it comes to the galley portion of the wall. It obviously doesn't need a ledge with no spars in that area. So, can I assume that the ledge cut out of the inner wall plywood would end at the rear portion of the doubled up spar for the galley hinge with sandwich wall aft of that left alone and matching the original template profile? There seem to be a variety of ways to skin this cat. I have seen a few examples of builders cutting a square notch through the entire wall to sit the galley hing spar into, or that is the way it appears. That looks like a method I'd like to use. I just want to make sure I am understanding this clearly before cutting the sandwich frame, and possibly ruining several hours of labor.
