I've just looked at the design in book 38, I don't believe there is anything wrong with the design. What could be confusing is the fact that the 14mm hole in the front bearing, item 64, is sleeved down to 8mm diameter by the tooth rest support clamp ring, item 75. This ring prevents the clamp screw marking the tooth rest support spindle which is only 8mm diameter.
Hope this helps.
Neil