I've given up in trying to reconnect with Bob Z. I even emailed his brother David who obviously mistook me for yet another autograph or memorabilia collector which I am not.
His hometown, Hibbing, Minnesota, is currently working on a big bash for Bob but he didn't show up for many earlier attempts. I think that his privacy has become more precious to him in the Autumn of his life.
I am sorry to hear that. It's a real shame that Dylan is so hard to contact. You could always try writing via that boxing gym / club that he owns (if he still owns it). Or, his agent - although maybe you have already tried methods like that.
I read last year that he and David had bought a place in Scotland, outside Inverness somewhere. I think that the article I read had a more precise location for it.
Where there's a will, there's a way.