Since the top of this sweater has some peculiar steps, I thought it might be useful to show pictures of the progress.
I first made the two neck extensions, adding an extra stitch along the outer edge of each (meaning the edge that will not be the free edge along the neckline) to give me a place to knit or purl up the sleeve stitches without losing my desired 11-stitch finished width of the front-neck edgings.