I finally completed a good trail from Langdale to the summit of Mt. Elphinstone.  The general idea is that people can get to the Sunshine Coast as a foot passengers (important in the Summer crush), hike/bike/hitch some 2 1/2 km up the highway to the trailhead, the summit being about 7-8 hours return from there. 

Early July would be perfect, with transport to trailhead arranged from this end, as I live on the SS Coast.  There are a few scrambly bits, so perhaps it should be rated B-C2.