Hi Alan, thanks for your prompt and comprehensive response. I was not sure if the deck plate was to be removed or not. Does the mast just slot into it with a rectangular 'tenon' fitting a hole in the deck plate?
On another note, we removed the mainsail and stack pack today and I managed to lose the sail track stop overboard. Unfortunately my clumsiness was witnessed by the Top Crew, so the incident has been filed away in case of need. Knurled screw down knob that stops the sail luff sliders slipping out of the mast luff groove. Quick search online shows Force 4 have a suitable product, but any better suggestions welcome.