My little rescue black and tan, Harley, is estimated to be going on 9 years old. He was deemed heart-clear a few months ago by a board certified cardiologist. He shows absolutely no signs of SM. He has a sweet, wonderful temperment. He is a cute as he can be. I have had several people tell me that if I ever need to rehome him to let them know, they would take him in a heart beat (ain't gonna happen!). A dog similar to Harley, with known background information, could offer valuable genetic diversity. No, he would never win in the show ring. But he is a wonderful lovely dog that would bring joy into anyone's life.
There may be cavaliers out there that could offer some genetic diversity and/or less CMSM without outcrossing to another breed of dog.
J. and pups, Gem, Monty, Harley and Sapphire