I checked my pattern pieces to see what I had done to change the pattern from single breasted to double. It was hard to see what was what, but it seems I just cut of one inch from the front piece. I am going to compare the pattern to the actual coat to see if I did anything else. I see by my original lines that I had planned to cut in in further, but don't know if I did it or not. I know that I basted the collar on and altered the shape a bit by eye, but made no changes to the pattern. Sorry I am not much help here.