Interesting Harbour on ebay...and the guy misspelled "surfboard" (he put surftboard...maybe because this board has been "surfed"?) Anyways, it is 7-4 single fin and the first bid is only $79.95. It is board #9846. Dude lives in Pomona. Might be an interesting addition to someone's collection (if I add it to mine my wife will add my jewels to her's!)
Here is the link:

http://cgi.ebay.com/Vintage-Harbour-Surftboard-serial-9846-7-4-one-fin_W0QQitemZ350073949988QQcmdZViewItem?hash=item350073949988&_trksid=p3286.m14.l1318