Hey Liz Neely, we have done just this type of thing with collection data from several institutions over the past 5 years or so and I thought you might be interested.
At Cogapp we’ve been using Solr rather than ElasticSearch as it wasn’t around at the time we started doing this but we’ve learned a lot that is applicable to ElasticSearch.
Project’s that might be of interest to you include the Met’s website (recently reskinned but the plumbing is the same I believe), the Qatar Digital Library (http://www.qdl.qa/en) as well as our work for the Yiddish Book Center (http://www.yiddishbookcenter.org/).
Anyway, happy to chat if it’s something that you are interested in. See you in Cleveland :-)