I have read the Golf-O-Metrics book from your grandfather, but never completely understood what he was trying say there.
With the video, everything is cleared up, the "seal of the wrists", the "cross lateral setup", the "Vardon drop".
I completely understand what he is talking about now, I guess a picture is worth a thousand words, and a video a million!
I can positively state that I have NEVER seen any golf instruction that is anywhere near to what your grandfather came up with, none!
All of the current "Pusher type swing" instructors, and NOT teaching what is in your video, and I can now see what is missing in their instruction that lets most people down, I bet the TGM guy has never seen these moves before either.
I plan on practicing this method and taking it to the course next week.
P.S. How old where you in the video when it was filmed??