H-9 Edge 540T Elevator Servos in Tail?
This is the view through the hole...you can see how the "filler" plate fits in. I used a sharpened pencil and some thin paper on the outside of the fusalage, took the side of the lead-pencil and "shaded" the outline of the cut-out. It transfered near perfect to the paper, that gave me a good starting point....