According to this database, they played Raleigh on April 8, 1970 and they also include a ticket stub and promotional poster advertising the date.
http://www.ledzeppelin-database.com/geekbaseweb/setpage.aspx?showid=220
Is it Achilles Last Stand? Now, if my ears do deceive me, if you listen closely to live versions, you can or may hear (or at least I hear for that matter) a click track.