EGOL, Everett,
Thank you both for your very useful suggestions. Sounds like we should do something similar to our PDF documents to represent them as the actual/canonical content on the page. And we'll look at our CMS to see how we might implement the unlinked page name in the breadcrumb. We have done some work already in adding structured data with schemas (including aggregate ratings), so that is hopefully yielding some results already.
However, after an encouraging traffic spike that seemed to indicate that we were on the right track, we saw a very worrisome dip last month.... which then led to a lot of worried hand wringing about Panda.
So these suggestions are very helpful ; thanks again and we'll try them out!
