Curiosity has gotten the best of me. Can you give an example(s) of where and when previously available exhibits were withdrawn?
Richard Frajola web site
http://www.philamercury.com has many exhibits free for the viewing. Maybe others can name additional resources. I have seen at least three.
Richard hosted the first digital single frame competition last September receiving 96 entries. He plans on hosting another this September.
Digital philately is coming of age with the "Union Catalog" of philatelic library holdings and many club web sites with both exhibits and documents.