No, it was not a typo. Years ago I was told that when the Mk III cam was designed they built in the quieting ramp by providing a ramp of about ten thou rising from the base circle over several tens of degrees. That sounds like it would provide a quieting ramp but having learnt a bit about cam design in a very amateurish way, I know that what might sound logical is not always correct. For example who would have thought that on the Swiss cam, a lower lift and flattish top to the curve, would have created more stress on the system? I just thought that is might be interesting to see what Vic's cams had in the way of a quieting ramp and what they did to the lift, velocity and acceleration curves.
Regarding the Tom Somerton copies of Picador cams, just remember that they have to be used with the correct radius curved followers.