Notice on all the devices you are looking at, the same thing is going on. Just as you suspected it is Machine Doubling
. A doubled die will show enlarged devices in the centers of the devices.
Note the spread on the centers of the devices and they are larger than normal in either height or width. Machine Doubling
reduces the size of the device by removing the contour of the devices.
Note on this one, the devices look distorted with widening:
Note also on the last set of images, that the contour is there, with the spread lines on the centers of the devices. Also they are wider than normal.
Side by side comparison with a normal set of devices and a DDO
Forget looking at the edges of the devices. Note the tops of the devices. Note the distortion. How some devices are affected differently. All these last 6 images are on the same two coins. One normal and one a doubled die. Hope this helps. If not, ask for answers to what confuses you.