Next came the pilot's headrest & life raft storage behind it. Carefully reviewing the scale plans & other reference sources revealed that the rear end of the headrest blends in with the vertical fin.
I carefully (Oh, ever so carefully to not disturb or crack the finish) I slowly cut out the rear portion, dry fitted the headrest to the vertical fin held temporarily in place , cut out a bit more, dry fitted & so on until I was satisfied with the results. I knew I was going to use a rounded file, followed by a # 400 sandpaper rolled up, so I made a small allowance for that extra clearance.