The link below is an eBay listing showing an Eisenhower autopen on a White House Card that has been authenticated by Beckett:

http://www.ebay.com/itm/President-Dwight-Eisenhower-Signed-Autograp...

If there's any question in your mind, here is a link showing that the Ike ia a well-known autopen (you'll need to scroll down or search for "Esienhower" to find the autopen):

http://www.stephenkoschal.com/news.html