A couple of satisfying hours on the Lathe. The internal dimensions of the pulley are all done. There's a few steps in there and a radius in the corner of one of the steps. Plenty of material removed.
A test fit on the water pump confirms the dimensions. It's a perfect snug fit. No bolts required to hold it in place.
Now to grind up a tool and cut the V grooves for the serpentine belt.
Cheers