Well, here goes my way! First, I get my buttplate shaped fairly close. I leave enough extra metal there because during the final cleanup, you will file and sandpaper shape across the matching door endpiece angle. That end piece has to match both the vertical arc of the plate and the continued outer arc of its shape. After the my box and door is inlet and door is fit to the sides, I let the door overlap the buttplate and mark where the outer plate edge is on the door. In answer to your question, the end inserts inside so you only see the door. I take a rough sized piece thicker than the other box material, and scribe around the inside of the shape of the door to get the compound shape. Remember, its at an angle! Its a test fit, but does solder inside the door. I let it run a little wild (meaning a little outside) so I can file it all to the plates angle. You know, this aint easy to explain is it!?!