ok..I had a moment of frustration with this question, but I'm ok now.
I might have found another piece to the puzzle in regard to the mountain posture first mentioned.
Started with a hunch, after looking at the Shorin kata 'Chinto' (which I haven't learned yet). Chinto was renamed by funakoshi to 'Gankaku'. It contains a similar posture (including the half-mountain) except this kata also includes the turn described. find out some apps for this and it may give ideas.
I have a sneaking suspicion this will be a repetitive process when trying to determine the postures that seem to be thrown into the TKD kata...I'm pretty sure most of these will come from Shorin kata.
anyway, have a look for yourself:http://www.nikawakai.co.uk/videos.htm
let me know if you see anything familiar...