Thanks Zagnut. However, I have read your description maybe 10 times and cannot understand it. You describe it as "single piece hub", but it seems from my interpretation of your text there are two separate components machined. Or have I got that confused?
How is the crankshaft retaining nut fitted and accessed? There is no mention of that.
At the end of paragraph 2 in your text above, is the hub removed from the lathe chuck and then the second piece of round stock chucked up in the lathe?
Many questions arising. Maybe because I am not a machinist/fitter and turner.