THE INSTITUTE OF MICROFILMED HEBREW MANUSCRIPTS has a website. In the past I have gotten microfilms of medieval Hekhalot manuscripts from them and Dr. Richler has always been very helpful. For those interested in such things, there is also an e-mail discussion list on Hebrew manuscripts to which I subscribe. Its message volume is low and generally pretty technical. It has a website and there is also an old page with an announcement of its inception which is a little more informative. (Scroll about three-quarters of the way down the page or do a page search for "Rabbi Yehoshua Scult".)