It was a messy job and I ended up with a very large hole in the deck. In this pic you can see where I removed the pulpit and also anchor chocks which were cast iron and rusting nicely.
A view from inside the boat showing the top of the tank I cut out and the hole in the deck.
This it afterwards I used three layers of fibreglass matt and epoxy resin then some epoxy with chopped strand to fill in the top. I was quite pleased with the result and I just need to blend in the gel coat to make a finish similar to the non slip deck but I am painting that anyway. Obviously I just needed to remove the wire and the disc of ply from inside.
Looking from inside, looks neat enough and might need to line this locker to cover where the tank was bonded inside the hull.
This is a pic after applying white gelcoat.
You can just see the round patch where the filler was removed and glassed over against the deck which has been sanded and given one coat of white primer. You can see the deck in the distance which is still discoloured and dirty. I am looking forward to seeing the whole deck painted with new non-slip areas.