I am making it in a pinstripe as shown in View B in the magazine which creates an interesting effect at the back. My fabric only has a small amount of stretch and the pattern calls for a stretch fabric so I have cut wide side seam allowances and am crossing my fingers!
I thought I could get away with cutting the back pieces with the fabric doubled but it must have slipped a bit as I just could not get the lines to meet up at the centre back seam. Luckily I had enough fabric to recut a back piece and I marked the lines onto the pattern piece to use as a guide to make sure my new right back piece matched the existing left back piece. This is where not adding seam allowances to my traced patterns is very helpful. So I recommend cutting the back pieces using a single layer if you are using a stripe or plaid.
Here is the back with the invisible zipper and godet sewn in.