Rickey Gates and I did the Complete Lost Coast (57 miles; King Range Beach and Sinkyone Wildernesss) from the Mattole River to Usal Beach in 13h47m on June 15, 2014.
I took 600 photos and Rickey carried a DSLR the entire way so the time can certainly be improved if soaking in the scenery is not a priority. Trip report: pantilat.wordpress.com/2014/07/04/complete-lost-coast-2/
Earlier in the Spring on March 23, 2014 Pantilat did a 50 mile route including the interior King Range and the beach section in 12h10m, the "King Range 50". Trip report: pantilat.wordpress.com/2014/04/25/king-range-50-at-the-lost-coast/