I pulled the mould apart last night and today a couple friends came around to help roll the hull over. I asked them around just in case the winching system didn't work as expected.
Turns out everything went off smoothly.
One of us wound webbing out of one winch while the other wound the opposite winch in. The hull rolled over and then we just wound both winches out so the hull could settle down on the supports that it will sit on until the outside is glassed.

I am thrilled with how straight and fair the hull half is. At this stage it looks like a light sand prior to glassing is all that will be required.
I must say taking my time heating the foam evenly in an oven and placing the foam with care has really paid off.
I just hope I can replicate these results on the next half.
Below are a couple of pics.