The top is cut out and I have constructed the knot front as per the instructions. It worked out fine.
I pinned it the front and back together and tried on. The back isn't great - especially at the top of the neck so I'll need to come up with something to address that - I think either gathering onto a strip of self fabric and turning under or a centre back seam.
However its paused for now until tomorrow evening when I will decide what to do.