Really helpful lady. Lots of good advice. We have a long road ahead, because he is severely lacking in confidence, though. He spent the first several minutes with his tail pinned firmly under his bottom 
So the advice is that we click when he looks at another dog, turn away and treat as we walk away. I think it's BAT?
He did really well with a lurcher used as as stooge dog, but was showing some signs of stress (he was getting more 'lungey' with the treat offered).
I'm hopeful that he may one day get to a place where he can display positive calm body language with other dogs, and not be so fearful.