OK, that method was a dead end, but I got closer to what I wanted to do by using a REST connection instead. I used the ListData.svc to call up the document set properties. Now I have access to the ID being used for each document set and can pair it up with the document set name.
But I still need to get the URL of the document set which also has the ID and name embedded. If I can bring in the URL as an assignable value, I can use it to compare the "current URL" with the ID or name value from the ListData service. But I can't find a data service that can grab this. Still looking.