Great job!! Love the harnesses. I make them also. The only difference is I make the D ring closer to the neck area. What ever works!
One of the earlier posters said the velcro on the bottem and neck make her nervous. I make my harnesses with the velcro on those places and have not had any problems. We walk Copper everyday and use this style harness. I do make sure the wrap around velcro has at least 2 inches of "stick" just to make sure.
Good luck with your sewing.