Now that my old senile mind thinks about it there is some radiusing done on stamped parts where the steel is compressed by the force of the shearing.....duh.

What looks like a parting line is probably just the other side of the sheared part. If he'd taken the pictures from more of an angle you could probably see it much better as a stamping. As far as the other photos go, they probably just dressed up the sheared edges by hand on a soft wheel to pretty it up some.