It took me a while to start actually riding my own horse without worrying about "messing up" what she had created. Once I started riding him like I always do, I became much more effective.
As I worked him, we both agreed that he has loads of potential. The one and only thing holding him back now is getting him to stretch across his top line. This isn't going to happen over-night. He's lived with a tight back for many years. It's going to be a long and slow process to elasticize and reshape his musculature.
The good thing is that someday, I will have a very lovely horse to show for it.