Dan the top of the backswing looked nice....I kind of drew some lines for you....your shoulders are staying too closed...you can see from the red line...note Palmer's shoulders are relatively square at this point...yours are pretty closed...this is keeping the clubhead/face from working OUT to the ball...note the direction the buttcap is looking...you need to get the shoulders turning and the buttcap starting to look back at you...note in the second pics how far back from the ball your clubhead is...it's not working down and out to the ball ...it's working underneath to the ball...that's where the shank is coming from...
So you need to feel like your left shoulder stays LOW and WORKS AROUND LOW BEHIND YOU...LEFT SHOULDER LOW AND AROUND...that will help get the clubhead to work out to the ball...also feel like buttcap is going to start looking back at you much earlier...remember this junk is happening FAST...so you may have to FEEL LIKE it is beginning to look back at you almost from the top as you start your downswing...
Note the arrows...left shoulder low and around right shoulder high and out....
a couple of things to experiment with...get a headcover or shoebox or something that you can't bust up to bad with a club or hurt yourself with...set it between your right foot and the ball...experiment with the placement but you are trying to put that thing in a place where if you come from "in and underneath" you'll crash the box...
also maybe try putting the ball waaaaay up in your stance I mean like outside your left toe and hit irons trying to hit pull cuts kind of...the way you are swinging from underneath you will have a tough time getting to that forward ball...film it and see if it changes the pictures....