The outer apron is strange too. It is not symmetrical. As you can see in this photo the crease on the left side is totally different from the right side.
Actually, the aprons of the kilts I make are not symmetrical, either. I always add an inch to the right hand apron edge just to make sure that the fringe edge covers the underapron. The kilt you're working on looks like it has a little more than an inch extra on the apron edge, but, if you look at your own Highland Granite, you'll see that the center front stripe is not in the numerical center of the apron!