What a delightful story! I love the idea of Severus keeping meticulous notes, but being unable to make his tongue form "R's"! It was a nice touch that Harry was better than Severus at this, and was so willing to help it at it. I also enjoyed the two more mature men able (and somewhat willing) to overcome the differences in their past.
Poor deluded Draco, what a hysterical way you had with him!