pomtzu, I think you are right about the socialisation in a way. Although he would have been used to other dogs I would imagine he was not walked whilst he was a stud dog and although he got used to being walked out whilst with the fosterer it was with other dogs in her care and more in a field/country situation.
I also agree about using a different type brush for grooming especially as he has hair as opposed to fur. I used an ordinary bristle brush yesterday and although he was a little suspicious he was fine. I've already sent for a plastic brush and a grooming glove and have hopes they will work better for him.

freedom, thank you for your advice. I agree that getting him to focus is the thing and I have done the thing with the sit and treats but although he does love his treats he has no interest at all when another dog is around. I think if we had a regular doggy walking companion it would be easier.