Here are some photos of my setup. I apologise if it's teaching someone to suck eggs but I am just trying to help with any misunderstandings!!!
No1 is the tool post with the thread on the top.
No2 is the box scraper platform.
No3 is the two screwed together.
No4 is the mdf with the faceplate screwed to it. The sandpaper is on the other side.
No5 is the faceplate screwed to the headstock drive.