I have figured out how to fill the last section of the planking. Kerfing! I had been scratching my head trying to figure out how to get the shape I need in the planking whilst filling in the gap in the planking and it finally occurred to me that kerfing was the answer. So I cut a few planks down to fill the gap vertically rather than horizontally and by kerfing the small sections I got them to bend to the curve of the deck and with the help of a lot of glue and bog the void was filled.
I smeared glue all over the place then overfilled it with bog. I covered the bog with peel ply to stop it sagging. I probably made the bog a little runny and its base was wet glue so in the end peel ply was the solution.
Now tomorrow morning I will run the sander over the area to shape it up a bit better, then I will glass the whole panel and hopefully also bog it whilst it is green to save having to sand it again. Then if I manage to get that done tomorrow, I will take the panel off the boat on Sunday and hopefully sand and glass it and get it back on the boat to set completing a good weekends work