This was sent to me by Bill Turner he met Mr. Shepard and this is what he had to say.  At the time he autographed the certificate he said that he was sure happy we were there to pick him up. He was very gracious while talking with him as he took extra time to talk to me. The officials kept telling him to hurry along and he responded, "I'll be right there after I finish talking to one of my boys".  This is a link to a webpage you might be interested in.  http://www.thespaceplace.com/history/mercury/mercury03.html