Hi Bandit

Without actually looking I not sure that proposal didn't go through, I stand to be corrected, but I think the centre beam stays.

With regards to your deck, I would start again from scratch, I would get a router if you have access to one, get a straight cutter bit, if the deck is say 6mm, set the router to 5mm and go nuts, start off near a hatch hole so you can make sure your not going all the way through.

Regards