Using that seam did you cut out 8mm from each edge? when I stick the 2 halves together the nose seems really wide and the circle nose piece looks small. But if I fold it over creating the B seam the nose appears to fit better. But I'm not sure what the correct seam is suppose to be used. Would assume that it would make a big difference since that is 1.6cm.
I also used "A" with a mylar strip on the back.
The plan has allready a 3.5mm seam allowance along the spine that makes a 7mm overlap (like all other seams) when you put both halfs together.
There is also a nose sewing pattern in 1:1 scale on the 2nd page of the plan. You can use it to compare the size