With the trailer back together I put the boat back on it for a short trip across my back yard to an open gazebo that has a substantial roof structure and enough headroom to turn the boat over in slings.
Here are a couple of photos of the boat on the trailer. You can see the overhang at the back of the boat, considerably less than it was and I plan to move the boat another 100 mm (4") forwards.
The next photo shows the boat lifted in rope slings passing through a couple of home made blocks (it would have been better, I think, to use webbing straps because the rope slings rolled along the curve of the hull and had to be restrained by tying them together).
Then turned halfway.
This is the most stable position for the boat supported in two slings, it turned to this position very quickly and then was hard to move to the upside down position. The problem was that, working by myself, I could turn the boat but then could not hold it in the upside down (unstable) position while lowering it onto a couple of sawhorses. In the end I use another 2 sets of blocks to pull down on the upper side and up on the lower side while lowering the boat onto the sawhorses. Tricky, but it's done.
Above shows the boat supported on sawhorses ready for work to begin on the bottom. Finally, a photo of the bottom which apart from dirt and few dings is in good condition. The main job is to finish the opening to the new centreboard case. The rows of holes are for the long screws that held the case in place while the epoxy set when it was installed. The woodwork where the centrecase logs come through the keel needs to be tided up. I will remove the paint around the wider section of the keel and put fibreglass cloth over the area and down into the case overlapping the cloth that is already inside the case and on the bottom of the boat.