So why if this not
Machine Doubling?
Machine Doubling will reduce the size of the devices. A doubled hub process creates on the die a wider taller set of devices. The affected areas are not a reduction of the devices, but a showing of spread on the devices. If this were
Machine Doubling, the affected area would be flat, showing a 90 degree angle, with the removal of the contour on the devices. ((inside/outside edges on the same direction will be altered by
Machine Doubling.
Here is a Side by side of a MD example and a
1963 plain DDO[ to see how much wider the devices could be on a spread compared to a normal die coin:

Again this is a Philly example, you can see the spread that your eyes should spot on these
DDO's on the quarter motto areas. (The closer the devices near the rim are affected more and sometimes that is part of the spread, or die wear on the spread area.) Die wear always affects the devices in the direction to the closest rims.