hey stew
I think till today u must have consult doc or physical therapist,so just would like to add more for your good self, well my observation is ur ant.delt is involved and during eccentric form mean when ur going down during movement ; so ur more target point is musculo-tendinous junction so as this injury is old ice is not preferable but still i suggest ice becuz its best healing medincine.rest ur part I have added correct form of exercise just see to it http://http://www.youtube.com/watch?v=c6I0z_d4xqY
our main target is when when doing exercise ur arm will not decline much and just see to the video that where the position of bar n dumbell is