ummm...trying to think here.....what I am thinking is that quilting a top usually shrinks the whole quilt down....I sometimes loss 3-4 inches when I quilt a large quilt....so what if you just cut the borders the same size as those outside measurements? Perhaps if you did a fairly close quilting design, the "background would shrink in the process to more match the center? are you planning on doing anymore quilting in the applique part? If so, I would do light quilting to minimize further shrinkage in that part....just an idea....don't know if this would work or not.....