Not a problem! Im more than happy to answer questions anytime on police procedure and how things work etc!
I think the idea that Ruth ran away and subsequently came to harm is highly likely. She would have been extremely vulnerable, both by virtue of her age but also because she lived a somewhat sheltered existence. It would have been easy for somebody to take advantage of her, whether by harming her physically or trafficking her etc.
I think the reason IW didn't want to engage is, as you say, because he was scared of the backlash he might receive or the further intrusion into his personal life. The thing is, at this point I think it's well passed that. It's nearly 30 years ago. A little publicity would potentially being about more leads and/or at least push the police into reviewing the case.