Be careful using sand paper on old glass. You reduce the belly, or back a fraction you can develope a hing in the tiller that will cause some major problems.
Good point. When you're sanding the limbs, be sure to use a sanding block,neversandacross the limband make all yourstrokes full length ofthelimb. Be sure to count the strokes and do exactly the same number on the other limb. I always do 10 strokes, then switch to the other limb and do 10 strokes. That way it's easier to keep up with.